Intermittent iron and folic acid supplementation for prevention of anaemia in menstruating women and adolescent girls

Transcription

1 WORLD HEALTH ORGANIZATION DEPARTMENT OF NUTRITION FOR HEALTH AND DEVELOPMENT EVIDENCE AND PROGRAMME GUIDANCE UNIT Intermittent iron and folic acid supplementation for prevention of anaemia in menstruating women and adolescent girls This submission was prepared by Hala Boukerdenna with technical input from Dr Juan Pablo Pena-Rosas and Dr Maria Nieves Garcia Casal. EML Section 10.1 Antianaemia Medicines

2 Table of Contents Acronyms and abbreviations... 2 Executive summary... 3 I. Background and rationale for the application... 5 II. Background on iron-deficiency anaemia Public health relevance Current public health interventions Proposed public health intervention... 6 III. Methods Methods for assessment of dosing, efficacy and safety Methods for the assessment of costs Methods for the assessment of current availability amongst Member States Assessment of the evidence... 8 IV. Regulatory information on iron supplements... 8 V. Analysis of costs... 9 VII. Current NEML availability evaluation VIII. Evidence on dosing, efficacy and safety of intermittent iron and folic acid supplementation Quality of the evidence Summary of the evidence IX. WHO guidelines on intermittent iron and folic acid supplementation X. Summary and recommendations XI. References

3 Acronyms and abbreviations BNF CI EML FA FDA GRADE IR IRR LMICs MHRA MSH NEML NTD RBC RR SRA TGA UK USD WHO British national formulary 95 % confidence interval Essential medicines list (for adults) Folic acid Food and Drug Administration Grading of Recommendations Assessment, Development and Evaluation Incidence rate Incidence rate ratio Low and middle-income countries Medicines and healthcare products regulatory agency Management sciences for health National essential medicines list Neural tube defect Red blood cell or erythrocyte Relative risk Stringent regulatory authority Therapeutic goods administration United kingdom United states dollar World health organization 2

4 Executive summary This application aims to request the inclusion of a supplementation dose of iron and folic acid to women during reproductive age in the Essential Medicines List. This document presents a comprehensive review of the evidence for the effective use of intermittent supplementation with 60 mg elemental iron plus 2.8 mg of folic acid in menstruating women and adolescent girls as a public health intervention in areas where anaemia prevalence is 20% or higher and where there are no interventions to control anaemia in place. These doses of iron and folic acid are currently recommended by the World health organization (WHO) guideline on Intermittent iron and folic acid supplementation in menstruating women. This document is a resubmission of an application reviewed by the 19 th Expert Committee of the Selection and Use of Essential Medicines in This new application provides additional data on the efficacy of weekly folic acid regimen on red blood cell (RBC) folate concentration and neural tube defects (NTDs) prevention. Evidence summarized in a Cochrane review shows that intermittent supplementation with iron (either alone or in combination with other nutrients) is significantly more effective in reducing anaemia among menstruating women compared to receiving no supplementation or placebo (average relative risk (RR) 0.73, 95% confidence interval (CI) 0.56 to 0.95). Evidence from 13 studies (2599 participants) showed a significant increase in haemoglobin concentration (mean difference (MD) 4.58 g/l, 95% CI 2.56 to 6.59) with supplementation. Additionally, 6 studies (980 participants) showed that supplementation significantly increases ferritin concentrations (MD 8.32 μg/l, 95% CI 4.97 to 11.66) compared to receiving no intervention or placebo. Benefits were observed with intermittent supplementation with iron when given either alone or in combination with folic acid or other micronutrients. However, compared to women receiving daily iron supplements, women receiving iron supplements intermittently were more likely to have anaemia (RR 1.26, 95% CI 1.04 to 1.51) and have lower serum/plasma ferritin concentrations (MD μg/l, 95% CI to -0.02, although they had similar haemoglobin concentrations (MD g/l, 95% CI to 1.91). The review found evidence that intermittent supplementation with iron (with or without folic acid) in menstruating women is effective in decreasing the risk of anaemia, and increasing haemoglobin and ferritin concentrations. Positive effects of intermittent supplementation were seen in patients receiving iron once or twice per week. Furthermore, the haematological responses were evaluated with supplements containing more or less than 60 mg of elemental iron per week for less or more than 3 months. The most common side-effects of iron supplementation include nausea, constipation, dark stools, and metallic taste. The current evidence suggests there is no significant difference in adverse 3

5 side-effects between once weekly intermittent iron supplementation versus no intervention or placebo (RR 1.98, 95% CI 0.31 to 12.72) and between once weekly intermittent iron supplementation versus daily iron supplementation (RR 0.36, 95% CI 0.10 to 1.31). The Essential Medicine List currently lists the fixed-dose combination ferrous salt + folic acid tablet equivalent to 60 mg iron μg folic acid. The recommendation of 2.8 mg is based on the rationale of providing seven times the recommended daily dose to prevent neural tube defects and on the experimental evidence that high weekly doses can improve red blood cell (RBC) folate concentrations to levels that have been associated with a reduced risk of neural tube defects (NTDs). Data on efficacy comparing the weekly to daily folic acid for prevention of neural tube defects is presented in this document. Evidence from two clinical trials on the prevention of NTDs showed that weekly folic acid supplementation (2.8 mg or 4mg) was not equivalent to daily 0.4mg supplementation. After 12 weeks, weekly folic acid supplementation showed a lower plasma folate concentration (MD , 95% CI [1.04 to 1.51]) and a lower RBC concentration (MD , 95% CI [ to 86.83]) compared to daily supplementation. However, both studies have shown that the rise in red blood cell folate concentration was linear and did not plateau during the length of the studies. After 12 weeks, the weekly 2.8mg reached a RBC folate concentration of 900 nmol/l (95% CI [828 to 978]) and after 6 months, the weekly 4mg supplementation reached a RBC folate concentration of nmol/l (95% CI [840.1 to 939.9]). Both concentrations are close to 906 nmol/l which has been defined as the threshold for optimal RBC folate concentration (NTDs). The recommendations for changes to the Essential Medicines List (EML) Section Antianaemia Medicines, are as follow: 1. Add 60 mg elemental iron in a ferrous form plus folic acid 2.8 mg tablet/capsule formulation for the prevention of anaemia in menstruating women and adolescent girls. The frequency and duration of the intermittent supplementation is as follow: a. One tablet per week b. Three months of supplementation followed by 3 months of no supplementation after which the provision of supplements should restart. i. If feasible, intermittent supplements could be given throughout the school or calendar year 4

6 I. Background and rationale for the application Daily supplementation with iron and folic acid for a period of 3 months has been the standard approach for the prevention and treatment of iron deficiency anaemia among women of reproductive age. Despite its proven efficacy, there has been limited success with the daily regimen public health programmes, which is thought to be primarily due to low coverage rates, insufficient tablet distribution and low adherence because of the sideeffects (e.g. constipation, dark stools or metallic taste). Intermittent use of oral iron supplements (i.e. once, twice or three times a week on non-consecutive days) has been used as an effective alternative to daily iron supplementation to prevent anaemia among menstruating women. The 18 th WHO Expert Committee (EC) requested a review of evidence to determine the appropriate dosing of iron and folic acid combination in menstruating women to prevent anaemia (1). A Cochrane review was commissioned to gather evidence in 2011, followed by the development of WHO guidelines on Intermittent iron and folic acid supplementation in menstruating women.(2)(3). This application presents evidence summarized in the Cochrane review and two additional studies with recommendations for the EML. II. Background on iron deficiency anaemia Iron-deficiency anaemia occurs as a result of decreased haemoglobin concentration in the blood and decreased iron concentrations, leading to iron deficiency (4). The causes of anaemia are several, including parasitic infections, inflammatory disorders, disorders of haemoglobin structure, or vitamin and mineral deficiencies, including iron and folate (4). It is estimated that at least half the burden of anaemia is due to iron deficiency and can be induced by sustained negative iron balance due to inadequate dietary intake, absorption or utilization of iron or chronic loss of iron due to bleeding (4). Women, during reproductive age, are at higher risk of developing iron deficiency due to menstruation. With prolonged iron deficiency, the haemoglobin concentration starts to decrease, resulting in iron deficiency anaemia (3). Haemoglobin is responsible for carrying oxygen from the lungs to the tissue; therefore, during anaemia, the blood has a decreased capacity to carry oxygen through the blood leading to a deficit of oxygen in the body of the affected individual, leading to a series of functional problems (3). Iron deficiency anaemia is diagnosed by measuring haemoglobin concentration, along with other iron status indicators such as serum ferritin and transferrin concentrations (5)(6). A decrease in these values by predefined laboratory measures that differ by age and sex indicate irondeficiency anaemia. 5

7 1. Public health relevance The world-wide prevalence of anaemia in non-pregnant women is estimated at 30.2%. Anaemia impairs resistance to infection and reduces physical capacity and work performance among all age groups (4). In addition, women with anaemia who become pregnant are at higher risk of negative maternal and neonatal outcomes (4). 2. Current public health interventions The standard approach used for prevention of anaemia in menstruating women where prevalence of anaemia is higher than 40% is daily supplementation with iron and folic acid for a period of 3 months (7). Although this method of supplementation is effective, the success with daily supplementation has been limited (7). This limited success is attributed to low coverage rates, insufficient supplement distribution, and low adherence due to the side-effects of iron supplements, such nausea, constipation, dark stools and metallic taste (4). In 2009 a temporary statement on Weekly iron and folic acid supplementation was released by WHO and updated in 2011 according to the procedures stipulated in the WHO handbook for guideline development. 3. Proposed public health intervention In order to minimize side-effects associated with iron supplementation and increase adherence, intermittent use of oral iron and folic acid supplements is recommended as an effective to prevent anaemia among menstruating women and adolescent girls in areas where no other interventions are in place or where daily iron supplementation has proven not to be effective. The rationale for this intervention is that intestinal cells turn over every 5 6 days and have limited iron absorptive capacity (3). Thus intermittent provision of iron would expose only the new epithelial cells to this nutrient, which may improve the efficiency of absorption (3). Intermittent supplementation may also reduce oxidative stress and the frequency of other side-effects associated with daily iron supplementation such as nausea and constipation as well as minimize blockage of absorption of other minerals due to the high iron levels in the gut lumen and in the intestinal epithelium (3). Furthermore, experience has shown that intermittent regimens may also be more acceptable to women and increase compliance with supplementation (8). Additionally, the use of this regimen can result in the improvement in women s folate status prior to pregnancy, which may help prevent some congenital anomalies, specifically neural tube defects (3). Child growth, development and risk of chronic disease later in life depend, in part, on maternal iron nutrition during pregnancy. The prevention of both anaemia and iron deficiency in menstruating women and girls prior to pregnancy and the assurance of desirable iron reserves prior to pregnancy is an important public health goal that requires multi-pronged, integrated and flexible approaches (8). Iron and folate deficiency may occur concurrently in menstruating women and girls, particularly during or after pregnancy. Because of the essential role for folate in 6

8 erythropoiesis, combined iron and folic acid supplementation may be required to ensure an optimal haematological response in menstruating women and adolescent girls. Because of the role of folate in preventing neural tube defects (9), women should have a folate level that is likely to protect against congenital anomalies before entering pregnancy, especially where pregnancies are not planned. The neural tube closes by day 28 of pregnancy, a period when pregnancy may not have been detected. Folic acid supplementation after the first month of pregnancy will not prevent neural tube defects, but will contribute to other aspects of maternal and fetal health. III. Methods 1. Methods for assessment of dosing, efficacy and safety Cochrane review: Intermittent iron supplementation for reducing anaemia and its associated impairments in menstruating women A Cochrane review was commissioned to determine if any evidence existed on intermittent iron and folic acid supplementation in menstruating women, and if so, what are the safe and effective doses of the interventions (2). The reviewers assessed randomized and quasi-randomized trials with either individual or cluster randomization in which the participants were non-pregnant women beyond menarche and prior to menopause (2). The intervention assessed was intermittent iron supplementation (with or without folic acid and other micronutrients) compared with a placebo, no intervention or daily supplementation (2). More than 10 international databases were searched and an equal number of international agencies were contacted for unpublished reports. Additionally, two clinical trials on the bioavailability of folic acid were assessed to determine whether 2.8mg weekly folic acid supplementation could increase RBC to concentrations that will reduce the risk of NTDs. The impact on the compliance among menstruating women and adolescent girls was also taken into account in order to identify the most effective regimen in terms of public health intervention. Study 1: Effects of once-a-week or daily folic acid supplementation on red blood cell folate concentrations in women. A 12 weeks, randomized controlled trial. Women were assigned to receive a daily placebo, a once-a-week 2.8 mg folic acid supplement, or a daily 0.4 mg folic acid supplement.(10) The authors choose 2.8 mg as the weekly dose because it was the same amount of folic acid given to the participants in the daily supplement group. The purpose 7

9 of this study was to determine if a once-a-week folic acid supplement increases women s red blood cell folate to concentrations that are associated with a low risk of NTD ( 905 nmol/l).(11) Study 2: Folate status and homocysteine response to folic acid doses and withdrawal among young Chinese women in a large-scale randomized double-blind trial. A double-blind randomized trial during six months.(12) The participants were randomly assigned to one of six intervention groups for which daily intakes of folic acid were 100 µg once a day, 25 µg four times a day, 400 µg once a day, 100 µg four times a day, 4000 µg once a day, or 4000 µg once a week. The purpose of this study was to evaluate the changes in folate concentrations in response to different folic acid doses.(12) 2. Methods for the assessment of costs For tablets containing 60 mg elemental iron and 2.8 mg folic acid, the 2013 edition of the International Drug Price Indicator Guide and the UNICEF Supply Catalogue website were searched.(13)(14) 3. Methods for the assessment of current availability amongst Member States A survey of National Lists of Essential Medicine (NEMLs) of 20 low and middle income countries was undertaken to determine availability of iron supplement formulations and folic acid supplements.(15) 4. Assessment of the evidence Strength and quality of evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) methodology (16). A table showing the characteristics of the studies with an evaluation of their quality is presented in Appendix A. IV. Regulatory information on iron supplements Both iron and folic acid supplements are currently on the EML for adults; furthermore, iron supplements are not reviewed for safety or efficacy and are not approved for sale as medications by the Stringent Regulatory Authorities (SRAs) in United States (Food and Drug Administration, FDA), Australia (Therapeutic Goods Administration, TGA) and the United Kingdom (Medicines and Healthcare products Regulatory Agency, MHRA)(13)(17). Rather supplements are registered as food supplements and are held to good manufacturing practices for purities only (17). Therefore, no additional specific analysis of regulatory status of iron or folic acid supplements was warranted. However, 8

10 manufacturers of supplements must be registered entities and certified to adhere to good manufacturing practices (18). V. Analysis of costs Commercial preparations with 66 mg of elemental iron and 2.8 mg of folic acid (Fermafolic 60) have been found in Panama from Laboratorios Prieto. This company currently provides this product through local pharmacies and has sold 5,000,000 tablets as part of a national health program for prevention of anemia in 2014 (see marketing authorization in Appendix D). Western Pacific Regional Office (WPRO) has been actively searching for a qualified manufacturer; however, the company making the product does not have all certificates yet. The most recent International Drug Price Indicator Guide (13) and the UNICEF Supply Catalogue (14) were used to compile the cost of iron and folic acid supplements. A combination formulation of ferrous salt 60 mg elemental iron plus 2.8 mg folic acid was not found. However, single nutrient formulations and the combination of only 60 mg elemental iron plus 0.4 mg folic acid tablets were found and are presented in the Table 1. Table 1 - Cost of tablets containing 60 mg elemental iron plus 2.8 mg folic acid Source Compound Form Cost per tablet or ml (USD)* MSH 2011 Ferrous Salt mg tab/cap (median) UNICEF Ferrous salt 60 mg tab MSH 2011 Folic Acid 5mg tab (median) UNICEF Folic acid 5 mg tabs MSH 2011 Folic Acid 1 mg tab (median) MSH 2011 Ferrous salt + folic acid 60 mg elemental iron (median) plus 0.4 mg folic acid UNICEF Ferrous fumarate + folic acid (tab) 60 mg elemental iron plus 0.4 mg folic acid (tab)

11 VI. Current NEML availability evaluation While there are several projects in countries targeting women and adolescent girls through weekly iron and folic acid supplementation, and it is now a policy for implementation in India, there was only one supplier found in Panama (Laboratorios Prieto) with the recommended formulation. National essential medicines lists (NEMLs) of 20 low and middle-income countries (LMICs) were reviewed to determine current availability of iron and folic acid supplements containing 60 mg elemental iron plus 2.8 mg folic acid combined, 60 mg of elemental iron tablets (either alone or in combination with folic acid), and folic acid supplements containing 1 mg or 5 mg per tablet/capsule (13). The table below shows that the majority of countries NEMLs contain iron and folic acid supplements. However, most NEMLs did not specify the elemental iron content of the formulations. None of the NEMLs surveyed contained a combination of 60 mg elemental iron with 2.8 mg folic acid. This is as expected since this formulation is not currently on the EML or EMLc, and most LMICs use the model WHO EML/EMLc to build their respective national formularies (15). 10

12 # country 60 mg elemental iron folic acid 1 mg folic acid 5 mg 60 mg elemental iron plus folic acid 2.8 mg Notes ( ) 1 Angola No Yes No Ferrous sulfate 200 mg found, unknown elemental iron content 2 Bangladesh No Ferrous salt liquid and tablet found, unknown elemental iron content. Folic Acid tablet found, unknown strength. 3 Bhutan Yes No Yes No Ferrous sulfate 60 mg tablet in combination with 0.4 mg folic acid 4 Central African Republic No Ferrous salt liquid and tablet found, unknown elemental iron content. Folic Acid tablet found, unknown strength. 5 China No Ferrous salt tablet found, unknown elemental iron content. Folic Acid tablet found, unknown strength 6 Democratic Republic of No Yes No Ferrous sulfate liquid and 200 mg + 5 mg folic acid tablet found, unknown elemental iron content Congo 7 Ecuador No Ferrous salt liquid and tablet found, unknown elemental iron content. Folic acid the NEML list tablet strength range mg. 8 Fiji No Yes No Ferrous salt liquid and tablet found, unknown elemental iron content. 9 Ghana Yes No Yes No Ferrous salt liquid found, unknown elemental iron content. 10 India No No No No Ferrous salt liquid and tablet (20mg elemental iron) in combination with 100mcg folic acid found. 11 Honduras Yes Yes No Ferrous salt tablet (65 mg elemental iron) found 12 Lesotho No Yes No Ferrous salt liquid and tablet found, unknown elemental iron content. 13 Malaysia No Yes No Ferrous salt tablet found, unknown elemental iron content. 14 Namibia No Yes No Ferrous salt tablet (65 mg elemental iron) found; Ferrous salt liquid found, unknown elemental iron content. 15 Oman Yes Yes No Ferrous salt tablet (45 70 mg elemental iron) found; Ferrous salt liquid (15 mg/0.6 ml elemental iron) found. 16 Pakistan Yes Yes Yes No 17 Rwanda Yes Yes Yes No 18 Senegal No Yes No Ferrous salt liquid and tablet found, unknown elemental iron content. 19 Thailand No Yes No Ferrous salt liquid and tablet found, unknown elemental iron content. 20 Vanuatu No Yes No Ferrous salt liquid and tablet found, unknown elemental iron content. 11

13 VII. Evidence on dosing, efficacy and safety of intermittent iron and folic acid supplementation Cochrane review: Intermittent iron supplementation for reducing anaemia and its associated impairments in menstruating women Pertinent outcomes of efficacy are presented here. Summary of Findings (GRADE) tables are presented in Appendix A to provide details on the evidence from which the recommendations were made (2). The review included 21 trials with 10,258 participants from 15 countries in Latin America, Africa and Asia from 1997 to In 11 of the 21 trials, the duration of supplementation was less than 3 months and in the others the maximum duration was 6 months (2). Iron alone was provided in nine trials, while eight trials assessed efficacy of iron plus folic acid supplementation and two studies used iron plus multiple micronutrient supplements (2). All except two trials used iron sulfate as the iron salt for supplementation (2). The Cochrane group undertook 6 comparisons of evidence: 1. Comparison 1: Intermittent iron supplementation versus placebo or no intervention 2. Comparison 2: Intermittent iron supplementation versus daily iron supplementation For each comparison listed, a summary of information on three outcomes (anemia, hemoglobin and ferritin) is provided in Appendix B. For each outcome, the following factors were considered: 1) the overall effect size of the intervention, 2) effect size with supplementation of 60 mg (or less) of elemental iron per week, 3) effect size with iron supplementation alone, and 4) effect size with supplementation of a combination of iron and folic acid. There are other several studies on folic acid absorption and retention in the body since 1975 and while there is plenty of evidence that 80%-100% of a folic acid dose may be absorbed, it seems clear that much less is retained and contributes to improved status. The fraction of a dose that is retained within the tissues seems to depend on the dose and ultimately on renal handling and the threshold where excess folic acid spills into the urine. Based on the two additional articles comparing weekly and daily folic acid supplementation, pertinent outcomes on plasma folate and RBC concentration are 12

14 presented in the Summary of Findings (GRADE) table in Appendix A. This table provides details on the evidence from which the recommendations were made. Study 1, Effects of once-a-week or daily folic acid supplementation on red blood cell folate concentrations in women Study 1 included 114 non pregnant women from New-Zealand with red blood cell folate concentrations between 295 and 905 nmol/l at screening (10). Those women with red blood cell folate greater than 905 nmol/l were excluded because they already had RBC folate concentrations with a very low risk of NTDs (11) and those having less than 295 nmol/l were excluded due to a folate deficiency (10). The majority of participants were young adult women (81% <30 years old) with no previous pregnancy (88%). Participant characteristics of the three treatment groups were not different. Women were randomized to receive a once-a-week 2.8 mg folic acid supplement (n=37), a daily 0.4 mg folic acid supplement (n=35) or a daily placebo (n=42) for a duration of 12 weeks.(10) The authors undertook two comparisons of evidence: weekly folic acid 2.8mg versus daily folic acid 0.4 mg and weekly folic acid 2.8mg versus placebo. Only one comparison (2.8mg versus 0.4 mg) was assessed in the Summary of Findings (Grade). Two outcomes: plasma folate concentration and red blood cell folate concentration were assessed at baseline, after six weeks and after 12 weeks. A summary of information on these two outcomes is provided in Appendix D. Study 2. Folate status and homocysteine response to folic acid doses and withdrawal among young Chinese women in a large-scale randomized double-blind trial. Study 2 included 1108 non pregnant women from 24 to 42 years old from China and lasted six months.(12) Plasma folate and red blood cell folate concentrations were measured at baseline; at one, three, six months; and three months after the interruption of folic acid. A placebo group was not included because the repeated-measures design of the study allowed each woman to serve as her own control.(12) The participants were randomly assigned to one of six intervention groups for which daily intakes of folic acid were 100 µg once a day, 25 µg four times a day, 400 µg once a day, 100 µg four times a day, 4000 µg once a day, or 4000 µg once a week.(12) In order to compare folic acid efficacy between the weekly and daily supplementation, only two comparisons of evidence from this study were analysed: daily 400 µg folic acid (n= 338) versus weekly 4000 µg folic acid (n=157). From this comparison, three outcomes: plasma folate concentration, red blood cell folate and homocysteine concentration were assessed at baseline, at one, three, six months; and three months after the interruption of folic acid supplementation. Homocysteine results were not taken into account in this document. A summary of information on plasma folate and RBC outcomes is provided in Appendix D. 13

15 1. Quality of the evidence Cochrane review: Intermittent iron supplementation for reducing anaemia and its associated impairments in menstruating women. The overall quality of evidence comparing intermittent iron supplementation to placebo or no intervention was low for outcomes of anaemia, haemoglobin, iron deficiency and ferritin(2). The overall quality of evidence comparing intermittent iron supplementation to daily supplementation was moderate for the outcome of anaemia; however, for the outcomes of haemoglobin and ferritin, the quality of evidence was low, and for iron deficiency it was very low (2). Study 1: Effects of once-a-week or daily folic acid supplementation on red blood cell folate concentrations in women and Study 2: Folate status and homocysteine response to folic acid doses and withdrawal among young Chinese women in a large-scale randomized double-blind trial. The overall quality of evidence comparing weekly versus daily folic acid supplementation was moderate for both, plasma folate concentration and red blood cell folate concentration outcomes.(10, 12) A table presenting the characteristics of the studies and an evaluation of their quality is presented in Appendix A. 2. Summary of the evidence Cochrane review: Intermittent iron supplementation for reducing anaemia and its associated impairments in menstruating women. The results from the systematic review show that intermittent supplementation with iron (either alone or in combination with other nutrients) is effective in reducing anaemia among menstruating women compared to no supplementation or placebo (RR 0.73, 95% CI 0.56 to 0.95)(2). Evidence from 13 studies (2599 participants) shows that there is a significant increase in hemoglobin concentration (MD 4.58 g/l, 95% CI 2.56 to 6.59) with supplementation (2). Additionally, six studies (980 participants) showed that supplementation significantly increases ferritin concentrations (MD 8.32 μg/l, 95% CI 4.97 to 11.66), compared to no intervention or placebo (2). Furthermore, the evidence shows that the benefits are seen with intermittent iron supplementation, either alone or in combination with folic acid or other micronutrients (2). The greatest benefits of 14

16 intermittent supplementation are observed in settings of moderate to high prevalence of anaemia (2). The evidence also shows that the effect on hemoglobin concentration is similar in patients who receive intermittent supplementation versus patients who receive daily iron supplementation (MD g/l, 95% CI to 1.91)(2). However, the mean difference in ferritin concentration was lower with intermittent supplementation compared to daily supplementation (MD μg/l, 95% CI to -0.02) and the risk of anaemia was higher in women receiving intermittent supplementation as compared to women receiving daily iron supplements (RR 1.26, 95% CI 1.04 to 1.51) (2). The review found evidence that intermittent supplementation with iron (with or without folic acid) in menstruating women is effective in decreasing risk of anaemia and increasing hemoglobin and ferritin concentrations (2). The positive effect of the intermittent supplement was seen in patients receiving iron once or twice a week (2). Furthermore, the hematological response was seen with supplementation containing more or less than 60 mg of elemental iron for a duration of more or less than 3 months (2). Although adherence has been claimed as one of the advantages of this intervention, its reporting is still inadequate. Results of three studies (556 participants) comparing adherence to intermittent iron supplementation versus no supplementation or placebo were not statistically significant (RR 0.99, 95% CI 0.96 to 1.01) (2). Four studies with 507 participants comparing intermittent supplementation to daily supplementation also found no difference in adherence (RR 1.04, 95% CI 0.99 to 1.09) (2). The most common side-effects of iron supplementation include nausea, constipation, dark stools and metallic taste (2). As shown in Appendix C, the current evidence suggests there is no significant difference is adverse side-effects between once weekly, intermittent iron supplementation versus no intervention or placebo (RR 1.98, 95% CI 0.31 to 12.72) and between once weekly intermittent iron supplementation versus daily iron supplementation (RR 0.36, 95% CI 0.10 to 1.31) (2). Study 1: Effects of once-a-week or daily folic acid supplementation on red blood cell folate concentrations in women. Folate concentrations at baseline were similar in all the three groups (10). In comparison to the placebo group, red blood cell folate concentrations in participants receiving the weekly and daily folic acid supplements were 39% (95%CI [28 to 52]) and 60% (95%CI [47 to 75]) higher, respectively, at week 12. Daily supplement users achieved a mean red blood cell folate concentration at week 12 that was 15% (95%CI [5 26]) or 137 nmol/l (95% CI [47 to 237]) higher than in weekly supplement users (10). Mean plasma folate concentration at week 12 was 46% (95%CI [26 to 70]) or 14 nmol/ l (95%CI [8 to 22]) 15

17 higher in daily than weekly supplement users (10). See Table 1 in Appendix D for more details. It was observed during the study that the increase in red blood cell folate concentrations in both folic acid groups was linear during the intervention while the change in plasma folate concentration was not; the increase was larger between weeks 0 and 6 than between weeks 6 and 12.(10) This difference can be explained by the fact that plasma folate is more sensitive to short-term dietary intake and its concentration increases rapidly following consumption of folic acid. (10) At week 12, 50% of women from the weekly supplement group achieved a red blood cell folate concentration greater than 905nmol/l while the same concentration was achieved by 74% of women in the daily 0.4 mg group.(10) However, in the weekly?? folic acid supplement group, the authors observed a rise in the RBC folate concentration that was linear (P<0.001) across weeks 0, 6 and 12 and did not plateau. They concluded that it is likely that a higher proportion of women in the weekly group would have exceeded 905 nmol/l with continued use of the folic acid supplements.(10) There is evidence from several studies that 905nmol/l of RBC folate concentration is a threshold above which the risk of NTDs is minimal.(10) For instance, a recent study (21) defines RBC folate concentration threshold for the prevention of NTDs at about 1000 nmol/l(21), and other study (11) suggests that the relationship between red blood cell folate and NTD risk is continuous so that a red blood cell folate concentration greater than 905 nmol/l may confer additional benefits. Nevertheless, the length of time to reach a steady state of red blood cell folate after initiating supplementation is still unknown. (22) Study 2: Folate status and homocysteine response to folic acid doses and withdrawal among young Chinese women in a large-scale randomized double-blind trial. Plasma folate concentrations among women who received 400 µg/day or 4000 µg/week were, respectively, 259% (95% CI, [240% to 279%]) and 142% (95% CI, [123% to 162%]) higher at 6 months than at baseline.(12) At 6 months, RBC folate concentrations were 71.8% (95% CI, [65.2%, to 78.4%]) and 45.7% (95% CI, [37.5% to 53.9%]) higher than those at baseline in the 400 µg/day and 4000 µg/week groups, respectively. At week 12, 400 µg/day and 4000µg/week supplementation groups reached RBC folate concentrations of nmol/l (95% CI, [879.8 to 949.7]) and 781.8nmol/L (95% CI, [739.2 to 827.0]), respectively (12). The average monthly increase in RBC folate concentration was 104 and 57 nmol/l in the 400 µg/day and 4000 µg/week groups, respectively. The 4000µg/week regimen (571µg/day average intake) was not as effective as 400µg/day during the 6 months follow-up. However, in all intervention groups, the 16

18 RBC folate concentrations did not plateau even after 6 months of folic acid administration (12). See Table 2 in Appendix D for more details. RBC concentrations decreased and 74.4 nmol/l/month during the 3 months after folic acid cessation in the 400 µg/d and 4000 µg/week groups, respectively. (12) The effects of folic acid on blood folate diminished relatively rapidly after cessation of folic acid intervention, and the predicted NTD risk reduction associated with supplemental folic acid intake would be rapidly lost if the supplementation is stopped. Results from studies 1 and 2 suggest that the starting time of the supplementation and its regular intake would be the important parameters to change the red blood cell folate level at the time of conception. There is evidence that only 50% of pregnancies are planned and it is unlikely that most women will take a daily folic acid supplement throughout their reproductive years (23). In this regard, the use of a once-a-week supplement may be an option for women not planning a pregnancy or for who daily supplement use is difficult. In New Zealand, for instance, 52% of people who use dietary supplements use them less than daily (10). As there is an established pattern of using dietary supplements episodically, it seems reasonable to expect that a once-a-week high dose folic acid supplement might be readily accepted by some.(10) In fact, the majority of studies in different parts of the world with populations of different ages and sex have shown that the weekly approach is efficacious and effective as well as more economical and more manageable in community settings (23). Indeed, in recent years, preventive supplementation with weekly iron-folic acid tablets has been considered by many developing countries as a new approach toward controlling anaemia and NTD risk in women of reproductive age. (24) For this reason, compliance and coverage should be seen as important criterions in the choice of the supplementation regimen in terms of a public health intervention. VIII. WHO guidelines on intermittent iron and folic acid supplementation The WHO Department of Nutrition for Health and Development released an interim statement in 2009 on weekly iron and folic acid supplementation (25), which was further informed by a Cochrane systematic review. These updated guidelines on intermittent iron and folic supplementation for menstruating women were published in 2011 (3). Even though the overall quality of evidence for outcomes of iron supplementation, intermittent or daily, with or without folic acid, ranges from low to moderate, the strength of the recommendation is strong (3). 17

19 The guideline development group felt that the evidence suggests that once weekly, intermittent supplementation with iron in menstruating women is effective in increasing haemoglobin and ferritin levels and in reducing the prevalence of anaemia and this is one of the few public health interventions widely supported by program experience (3). Intermittent supplementation with iron and folic acid in women, delivered by variety of channels, has been a successful intervention in several countries (Cambodia, Egypt, Laos, the Philippines and Viet Nam), reaching over a half a million women. In general, the compliance has been high, with a decrease in the prevalence of anaemia between 9.3% and 56.8% (8). Furthermore, citing experimental evidence, the guidelines provide a strong recommendation for using 2.8 mg folic acid alongside 60 mg elemental iron to reduce risk of neural tube defects in a fetus should the woman or adolescent girl become pregnant (2)(5). The evidence points out that 2.8 mg of folic acid weekly in New Zealand is efficacious in elevating erythrocyte folate concentrations above 905 µmol/l (10). Similar results have been observed with 4 mg weekly dose in China and with 5 mg in Mexico (12)(19). In intervention trials where supplements containing up to 5 mg of folic acid per day were administered during pregnancy, there was no evidence of toxicity or additional side-effects when compared to women receiving a placebo (20). Therefore, WHO guidelines recommend the following schedule of iron and folic acid supplementation as a public health intervention to reduce the risk of anaemia in menstruating women and neural tube defects in newborn children for menstruating women and adolescent girls living in settings where anaemia is 20% or higher (5). Table 2 - Suggested scheme for intermittent iron and folic acid supplementation in menstruating women Target Group Supplement composition Supplement form Frequency Duration and time interval between periods of supplementation All menstruating adolescent girls and adult women Iron: 60 mg of elemental iron* Folic acid: 2800 μg (2.8 mg) Tablets/capsules One supplement per week 3 months of supplementation followed by 3 months of no supplementation after which the provision of supplements should restart. If feasible, intermittent supplements could be given throughout the school or calendar year Settings Populations where the prevalence of anaemia among nonpregnant women of reproductive age is 20% or higher *60 mg of elemental iron equals 300 mg of ferrous sulfate heptahydrate, 180 mg of ferrous fumarate or 500 mg of ferrous gluconate. 18

20 IX. Summary and recommendations There is sufficient evidence to show that intermittent supplementation with iron and folic acid is a feasible and effective public health policy to decrease the risk of anaemia in menstruating women and adolescent girls. The addition of folic acid can help prevent neural tube defectaffected pregnancies should a woman become pregnant. The recommendations for changes to the EML Section Antianaemia Medicines, are as follows: 1. Add 60 mg elemental iron in a ferrous form plus 2.8 mg folic acid tablet/capsule formulation for the prevention of anaemia in menstruating women. a. Dose i. 60 mg of elemental iron equals 300 mg of ferrous sulfate heptahydrate, 180 mg of ferrous fumarate or 500 mg of ferrous gluconate. b. Frequency and duration of intermittent supplementation i. Once weekly for menstruating women for three months followed by 3 months of no supplementation, after which the provision of supplements should restart. ii. If feasible, intermittent supplements could be given throughout the school or calendar year. 19

21 X. References 1. Report of the 18th WHO Expert Committee: The Selection and Use of Essential Medicines. Geneva: World Health Organization, Fernandez Gaxiola AC, De Regil LM. Intermittent iron supplementation for reducing anaemia and its associated impairments in menstruating women. Cochrane Database of systematic Reviews. 2011(12):CD Epub 2011/12/ Guideline: Intermittent iron and folic acid supplementation in menstruating women. Geneva, Switzerland: World Health Organization, Stoltzfus RJ. Iron interventions for women and children in low income countries. Journal of Nutrition 2011;141:S756 S Haemoglobin concentrations for the diagnosis of anaemia and assessment of severity. Vitamin and Mineral Nutrition Information System. Geneva, World Health Organization, 2011 (WHO/NMH/NHD/MNM/11.1) ( accessed 1 November 2012). 6. WHO/CDC. Assessing the iron status of populations: report of a joint World Health Organization/ Centers for Disease Control and Prevention technical consultation on the assessment of iron status at the population level. Geneva, World Health Organization, Available at 7. WHO/UNICEF/UNU. Iron deficiency anaemia: assessment, prevention and control, a guide for programme managers. Geneva, World Health Organization, Available at 1.3/en/index.html. 8. Weekly iron and folic acid supplementation programmes for women of reproductive age: an analysis of best programme practices. Manila, World Health Organization Regional Office for the Western Pacific, De Regil LM, Fernández Gaxiola AC, Dowswell T, Peña Rosas JP. Effects and safety of periconceptional folate supplementation for preventing birth defects. Cochrane Database Syst Rev. 2010;(10):CD Norsworthy B, Skeaff CM, Adank C, Green TJ. Effects of once a week or daily folic acid supplementation on red blood cell folate concentrations in women. Eur J Clin Nutr Mar;58(3): Daly LE, Kirke PN, Molloy A, Weir DG, Scott JM. Folate levels and neural tube defects. Implications for prevention. JAMA Dec 6;274(21): Hao L, Yang Q H, Li Z, Bailey LB, Zhu J H, Hu DJ, et al. Folate status and homocysteine response to folic acid doses and withdrawal among young Chinese women in a large scale randomized doubleblind trial. Am J Clin Nutr Jan 8;88(2):

22 13. MSH. International Drug Price Indicator Guide. Management Sciences for Health, Unicef supply chain catalogue [Internet]. UNICEF. [cited 2014 Oct 23]. Available from: National Medicines List/Formulary/Standard Treatment Guidelines. World Health Organization; 2012 [cited 2012 November 1st]; Available from: GRADE working group [Internet]. [cited 2014 Oct 23]. Available from: MHRA. United Kingdom Medicines and Healthcare Products Regulatory Agency [cited 2014 September 29st]]; Available from: Laing R, Waning B, Gray A, Ford N, t Hoen E. 25 years of the WHO essential medicines lists: progress and challenges. Lancet. 2003;361(9370): Epub 2003/05/ Martínez de Villarreal LE, Arredondo P, Hernández R, Villarreal JZ. Weekly administration of folic acid and epidemiology of neural tube defects. Maternal and Child Health Journal Sep;10(5): Peña Rosas JP, De Regil LM, Dowswell T, Viteri FE. Daily oral iron supplementation during pregnancy. In: The Cochrane Collaboration, editor. Cochrane Database of Systematic Reviews [Internet]. Chichester, UK: John Wiley & Sons, Ltd; 2012 [cited 2014 Nov 26]. Available from: on_anaemic_pregnancy/en/ 21. Crider KS, Devine O, Hao L, Dowling NF, Li S, Molloy AM, et al. Population red blood cell folate concentrations for prevention of neural tube defects: Bayesian model. BMJ. 2014;349:g Schorah CJ. Folic acid food fortification to prevent neural tube defects. Lancet Mar 14;351(9105):834; author reply Viteri FE, Berger J. Importance of pre pregnancy and pregnancy iron status: can long term weekly preventive iron and folic acid supplementation achieve desirable and safe status? Nutr Rev Dec;63(12 Pt 2):S Khan NC, Thanh HTK, Berger J, Hoa PT, Quang ND, Smitasiri S, et al. Community mobilization and social marketing to promote weekly iron folic acid supplementation: a new approach toward controlling anemia among women of reproductive age in Vietnam. Nutr Rev Dec;63(12 Pt 2):S Weekly iron folic acid supplementation (WIFS) in women of reproductive age: its role in promoting optimal maternal and child health. Position statement. Geneva, World Health Organization, 2009 ( accessed 10 December 2012). 21

23 1. Appendix A: Summary of Findings (GRADE) tables 1.Intermittent use of iron supplements versus placebo or no intervention 22

24 2. Intermittent versus daily use of iron supplements 23

25 3. Weekly versus daily folic acid supplementation GRADE Summary of findings tables Weekly folic acid versus daily folic acid Patient or population: Women in reproductive age Settings: All settings Intervention: weekly folic acid (2.8mg and 4mg) Comparison: daily folic acid 400 µg Outcomes Plasma folate concentration (nmol/l) Relative effect or mean difference (95% CI) Number of participants (studies) Quality of the evidence (GRADE)* Comments MD 12.5 ( ) (2 studies) 567 Moderate 1 Red blood cell folate concentration (nmol/l) MD ( ) (2 studies) 567 Moderate 1 CI, confidence interval; RR, risk ratio; MD, mean difference. *GRADE Working Group grades of evidence: High quality: We are very confident that the true effect lies close to that of the estimate of the effect. Moderate quality: We have moderate confidence in the effect estimate. The true effect is likely to be close to the estimate of the effect, but there is a possibility that it is substantially different. Low quality: Our confidence in the effect estimate is limited. The true effect may be substantially different from the estimate of the effect. Very low quality: We have very little confidence in the effect estimate. The true effect is likely to be substantially different from the estimate of the effect. 1 Two studies with minor limitations: inadequate loss of follow up, unclear blinding and unclear sequence of generation ( see below characteristics of the studies and quality assessment of the evidence for more details) 24

26 A. Characteristics of the studies and quality assessment of the evidence Study 1: Effects of once a week or daily folic acid supplementation on red bllod cell folate concentration in women (Norsworthy, 2004)(10) Methods Randomised controlled trial. Randomization: Treatment assignment took place after all women had been screened. In rank order of red blood cell folate concentrations women were randomized to the intervention groups. Blinding: Supplements were in sealed bottles and were identical in size and similar in colour. The treatment codes remained sealed until all data analyses had been completed. A weekly placebo was not used in the study, consequently, participants assigned to take the once a week supplement would have known they were receiving folic acid. Loss to follow up: In total, 24 women were lost to follow up (22.8%) from 138 women were randomized to the treatment groups. In all, 13 withdrew from the study due to time constraints and 11women with missing plasma and red blood cell folate data at week 6 or 12 were excluded from the final statistical analysis. Exclusion of these women made little difference to the magnitude of the treatment effects. Participants Number: 114 pregnant women Inclusion/ Exclusion criteria: Women were excluded if they consumed a supplement containing more than 100 µg/day of folic acid in the previous 3 months, if they were taking drugs known to interfere with folate metabolism, or if they had established chronic disease. We also excluded women who had been pregnant in the previous year, were planning a pregnancy, or had a prior history of a neural tube defect affected pregnancy. Women with red blood cell folate concentrations between 295 and 905 nmol/l were eligible and invited to participate. The study only included women for whom a complete set of blood results was available. Interventions Women were assigned to receive a 0.4 mg daily placebo, a once aweek 2,8 mg folic acid supplement, or a daily 0.4 mg folic acid supplement 25

27 Outcomes Red blood cell folate and plasma folate concentration Notes Compliance was calculated as the proportion of prescribed pills taken during the study and was assessed in the daily and placebo groups by weighing the remaining pills and in the once a week group by counting the unused pills. Risk of bias Adequate sequence generation? Authors judgement Yes Description Unclear: In rank order of red blood cell folate concentrations women were randomized to the intervention groups. Allocation concealment? Yes Adequate Blinding? All outcomes Unclear Unclear Incomplete outcome data addressed? All outcomes Yes Inadequate: 22.8% Factors lowering the quality of evidence Study limitations It is not clear if it is a double blind or a single blind trial. Inadequate loss of follow up (22.8%) Minor Limitation Consistency Directness Imprecision Reporting bias The results of the two studies comparing weekly and daily folic acid are consistent. Direct measurement of red blood cell folate and plasma folate. No imprecision: 114 participants. This study is one of the two studies found comparing weekly and daily folic acid supplementation. No additional studies were found. 26

28 Study 2: Folate status and homocysteine response to folic acid does and withdrawal among young Chinese women in a large scale randomized double blind trial (Hao, 2008)(12) Methods Double blind randomized control trial Randomisation: 1108 women were randomly assigned to 1 of 6 intervention groups. Equal number of women was assigned to each group. Blinding: Women were issued an identification card linking their identity with assigned supplements, which were given out weekly in each subject's home by trained village physicians, who also monitored the subject's health status and compliance with the pill taking protocol. Loss to follow up: Among 1108 women, 107 dropped out after 1 month (9.6%). Participants Number: 1108 women Inclusion/ Exclusion criteria: Eligible women included residents of the townships who were not anemic (hemoglobin > 12 g/dl) or vitamin B 12 deficient (plasma vitamin B 12 concentration > 148 pmol/l). Additional eligibility criteria included no chronic disease (eg, hypertension, diabetes, cancer, or epilepsy); no supplement use within the past 3 months; no routine use of prescription medication; no current pregnancy or breastfeeding; delivery of an infant 2 4 years before the initiation of the study; no plans to become pregnant within the next 9 months; and use of an intrauterine device (IUD) for contraception. Interventions Women were randomly assigned to 1 of 6 intervention groups for which daily intakes of folic acid for 6 months were 100 μg 1 time/day, 25 μg 4 times/day, 400 μg 1 time/day, 100 μg 4 times/day, 4000 μg 1 time/day, or 4000 μg 1 time/week. Outcomes Plasma, red blood cell folate and homocysteine (not included in Grade Tables) concentrations were measured at baseline; at 1, 3, and 6 months; and 3 months after the discontinuation of folic acid. Risk of bias Adequate sequence generation? Authors judgement Yes Description Unclear: Does not specify the method. Allocation concealment? Yes Adequate: Identification card linking their identity with assigned supplements. Blinding? All outcomes Yes Double blind 27

29 Incomplete outcome data addressed? All outcomes Yes Adequate: 9.6% Factors lowering the quality of evidence Study limitations The sequence generation is unclear. Minor limitations Consistency Directness Imprecision Reporting bias The results of the two studies comparing weekly and daily folic acid are consistent. Direct measurement of red blood cell folate, plasma folate and homocysteine. (Not included in the GRADE tables). No imprecision: 1108 participants This study is one of the two studies found comparing weekly and daily folic acid supplementation. No additional studies were found 28

30 B. Appendix B: Dosing and efficacy evidence 1. Comparison 1: Intermittent iron supplementation versus placebo or no intervention Comparison 1: Intermittent iron supplementation versus placebo or no intervention # Outcome No of Studies No of Participants Effect size (RR*) 1 Anaemia (for all) [0.56, 0.95] 2 Anaemia with 60 mg (or less) elemental iron per week [0.43, 1.10] 3 Anaemia by intervention (iron alone) [0.09, 2.13] 4 Anaemia by intervention (iron plus folic acid) [0.64, 1.04] RR = average relative risk Comparison 1: Intermittent iron supplementation versus placebo or no intervention # Outcome No of Studies No of Participants Effect size (MD*) 1 Haemoglobin (for all) 2 Haemoglobin with 60 mg (or less) elemental iron per week 3 Haemoglobin by intervention (iron alone) 4 Haemoglobin by intervention (iron plus folic acid) MD = Mean Difference g/l [2.56, 6.59] 5.21 g/l [2.06, 8.36] 6.13 g/l [1.90, 10.36] 3.56 g/l [1.11, 6.01] Comparison 1: Intermittent iron supplementation versus placebo or no intervention # Outcome No of Studies No of Participants Effect size (MD*) 1 Ferritin (for all) μg/l [4.97, 11.61] 29

31 2 Ferritin with 60 mg (or less) elemental iron per week μg/l [7.06, 17.69] 3 Ferritin by intervention (iron alone) μg/l [1.38, 14.23] 4 Ferritin by intervention (iron plus folic acid) μg/l [3.23, 8.52] MD = Mean Difference 30

32 2. Comparison 2: Intermittent iron supplementation versus daily iron supplementation Comparison 2: Intermittent iron supplementation versus daily iron supplementation # Outcome No of Studies No of Participants Effect size (RR*) 1 Anaemia (for all) [1.04, 1.51] 2 Anaemia with 60 mg (or less) elemental iron per week [0.82, 1.85] 3 Anaemia by intervention (iron alone) [0.97, 1.99] 4 Anaemia by intervention (iron plus folic acid) [0.98, 1.53] RR = average relative risk Comparison 2: Intermittent iron supplementation versus daily iron supplementation # Outcome No of Studies No of Participants Effect size (MD*) 1 Haemoglobin (for all) g/l [ 2.20, 1.91] 2 Haemoglobin with 60 mg (or less) elemental iron per week g/l [ 0.34, 2.62] 3 Haemoglobin by intervention (iron alone) g/l [ 1.15, 1.78] 4 Haemoglobin by intervention (iron plus folic acid) g/l [ 6.10, 4.13] MD = Mean Difference Comparison 2: Intermittent iron supplementation versus daily iron supplementation # Outcome No of Studies No of Participants Effect size (MD*) 1 Ferritin (for all) μg/l [ 22.61, 0..02] 31

33 2 Ferritin with 60 mg (or less) elemental iron per week 3 Ferritin by intervention (iron alone) 4 Ferritin by intervention (iron plus folic acid) MD = Mean Difference 32

34 C. Appendix C: Safety profile of iron supplementation 1. Intermittent iron supplementation versus placebo or no intervention Intermittent iron supplementation versus placebo or no intervention # Outcome No of Studies No of Participants Effect size (RR*) 1 All cause morbidity [0.82, 1.52] 2 Any side effects [0.31, 12.72] 3 Diarrhea [0.05, 1.49] RR = average relative risk 2. Intermittent iron supplementation versus daily iron supplementation Intermittent iron supplementation versus daily iron supplementation # Outcome No of Studies No of Participants Effect size (RR*) 1 Diarrhea [0.12, 49.43] 2 Any side effects [0.10, 1.31] RR = average relative risk Appendix D: Comparison between weekly and daily folic acid Table 1: Estimated geometric means (and 95% CI) of folate concentrations at different follow up times of the B Norsworthy study. Follow up times 400 µg/day 2800 µg/week (n = 35) (n = 37) Plasma folate concentration (nmol/l) Baseline 6 weeks 12 weeks 18 (16 to 21) 38 (32 to 43) 44 (39 to 49) 20 (17 to 24) 28 (25 to 32) 32 (28 to 36) 33

35 RBC folate concentration (nmol/l) Baseline 6 weeks 615 (560 to 677) 863 (797 to 935) 608 (553 to 668) 747 (685 to 816) 12 weeks 1053 (957 to 1158) 900 (828 to 978) Table 2: Estimated geometric means (and 95% CI) of folate concentrations at different follow up times of the Ling Hao study. Mean folate concentrations Follow up times 400 µg/day Folic acid dose 4000 µg/week (n = 338) (n = 157) Plasma folate concentration (nmol/l) 95% CI Baseline 1 month 3 months 6 months 9.6 (9.1 to 10.2) 29.8 (28.3 to 31.5) 36.5 (34.5 to 38.5) 34.5 (32.7 to 36.5) 9.8 (9.0 to 10.6) 20.9 (19.3 to 22.7) 23.9 (22.0 to 25.9) 23.7 (21.8 to 25.6) 9 months* 16.6 (15.9 to 17.3) 14.3 (13.4 to 15.2) RBC folate concentration (nmol/l) Baseline 1 month (580.5 to 626.6) (701.4 to 757.1) (577.5 to 646.1) (603.6 to 675.2) 95% CI 3 months (879.8 to 949.7) (739.2 to 827.0) 6 months (996.6 to ) (840.1 to 939.9) 9 months * (700.9 to750.5) (632.6 to 699.9) *Interruption of folic acid supplementation at 6 months. 34

36 Document 1: Marketing authorization of Fermafolic 60 from Laboratorios Prieto 35