Continuing Education for Pharmacy Technicians Dietary Supplements: Calcium and Vitamin D

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2 Continuing Education for Pharmacy Technicians Dietary Supplements: Calcium and Vitamin D Ashley Elliott, PharmD candidate Julie N. Bosler, PharmD McWhorter School of Pharmacy Birmingham, AL Objectives: At the conclusion of this lesson, successful participants should be able to: 1. Describe the age recommendations for daily intake of calcium and vitamin D. 2. Explain the differences in the available supplement products. 3. Recognize common drug and food interactions with calcium and vitamin D. Introduction Maintaining good bone health is a very important precursor to preventing osteoporosis and fractures. There are several interventions that can be made to prevent both of these, including adequate calcium and vitamin D intake, regular weight-bearing and muscle-strengthening exercise, and avoiding alcohol and tobacco consumption. 1 Bone is continuously remodeled, and as we age the balance of bone resorption and deposition changes. In older adults, bone breakdown occurs more than rebuilding which results in bone loss and an increase risk of osteoporosis and fractures. 2 Functions and Sources of Calcium Calcium is the most abundant mineral in body. It is required for vascular and muscle functioning, nerve transmission, and some hormonal secretions. 2 However less than 1% of our total body calcium is needed to support these functions. 2 The remaining 99% of the body s supply is stored in bones and teeth where it works to support their structure. 2 There are several sources of calcium including foods, supplements, and some medications. Milk, yogurt, and cheese are the highest contributors of calcium from food products in the United States. Other food sources include broccoli and fortified grains, juices, drinks, and cereals. 2 Some common over-thecounter antacid products also contain calcium. Calcium supplementation Individuals who fail to meet the adequate daily intake of calcium (Table 1) should consider adding a calcium supplement. Other individuals who would benefit from supplements include osteopenia or osteoporosis patients, perimenopausal or postmenopausal women, vegans, mothers who breastfeed multiple infants, amenorrehic women, residents of long-term care facilities, lactose intolerant individuals, and those receiving chronic corticosteroid therapy. 3 2

3 Table 1. Recommended Dietary Allowances for Calcium 2 Age Male Female Pregnant Lactating 0-6 months 200 mg 200 mg 7-12 months 260 mg 260 mg 1-3 years 700 mg 700 mg 4-8 years 1000 mg 1000 mg 9-13 years 1300 mg 1300 mg years 1300 mg 1300 mg 1300 mg 1300 mg years 1000 mg 1000 mg 1000 mg 1000 mg years 1000 mg 1200 mg 71+ years 1200 mg 1200 mg Available Supplemental Sources There are several available calcium products to supplement a patient s intake. Calcium carbonate and calcium citrate are the most commonly used. Several factors may come into play when trying to decide which form is the best for each patient. The use of H 2 blockers or a protein-pump inhibitor (PPI), number of tablets needed or size of tablets, and cost should all be considered when choosing which source is best. 3 Common side effects of calcium supplementation include gas, bloating, and constipation. Absorption of calcium is greatest when 500mg or less is taken per dose. 3 Calcium Carbonate: This form of calcium is most commonly available, as well as inexpensive. However, patients with reduced stomach acidity (patients taking H 2 blockers or a PPI) can have impaired absorption 2. In these patients it may be more advisable to recommend another source, such as calcium citrate. Calcium carbonate should be taken with food to decrease the gastrointestinal side effects associated with calcium use. This formulation contains 40% elemental calcium, the highest concentration of the supplemental sources. 3 Calcium Citrate: This available form is also very common but is more expensive than calcium carbonate. It has 21% elemental calcium so more tablets or capsules would need to be taken to achieve the correct daily dose. 3 Calcium citrate should be recommended in patients with achlorhydria (insufficient hydrochloric acid), inflammatory bowel disease, absorption disorders, and in patients taking medications that can affect stomach acidity. 3 Calcium Lactate: This is a less common form and only contains 13% elemental calcium. 3 Calcium Gluconate: This form contains only 9% elemental calcium. 3 3

4 Calcium-Drug/Food Interactions 2,3 The table below provides a list of common drug and food interactions with calcium. Levothyroxine H 2 blockers and PPIs Tetracylines Quinalone antibiotics Bisphosphonates Thiazide diuretics Corticosteroids Anticonvulsants, Phenytoin, Fosphenytoin, Carbamazepine, Phenobarbital Caffeine Sodium Functions and Sources of Vitamin D Concomitant calcium intake reduces levothyroxine absorption Decrease absorption of calcium carbonate Calcium decreases absorption; should be taken 2 h before or 4-6 h after calcium Should be taken at least 30 min before calcium Decrease excretion of calcium Decrease calcium absorption and increase calcium excretion Decrease calcium absorption by increasing metabolism of vitamin D Intake >300 mg/day increases urinary excretion of calcium Increases urinary calcium excretion Vitamin D is one of the four fat-soluble vitamins. Vitamin D 2 (ergocalciferol) comes from a plant sterol and yeast. Vitamin D 3 (cholecalciferol) is made in the skin by a cholesterol precursor when ultraviolet rays strike the skin and trigger the synthesis. 4,5 Vitamin D 3 may be at least three times as effective as vitamin D 2 at increasing and maintaining vitamin D levels in the body. 4 Some fracture studies have also shown that cholecalciferol is more effective at decreasing fracture risk. 4 Vitamin D has several functions in the body. It has a role in cell growth, neuromuscular and immune function, and reducing inflammation. 5 Perhaps the most important function, however, is its role in bone health. Vitamin D enhances calcium absorption and helps to maintain adequate levels of calcium and phosphate, thereby enabling bone mineralization. 5 The vitamin is also needed by osteoblasts and osteoclasts for bone growth and remodeling. 5 Vitamin D is present in some food sources, such as the flesh of fatty fish (salmon, tuna, and mackerel), fish liver oils, beef liver, cheese, and egg yolks. Vitamin D in food sources is primarily in the form of vitamin D 3 and its metabolite 25(OH)D 3. 5 Fortified foods provide the most vitamin D in our diets. Milk in the United States is fortified with 100 IU/cup and some breakfast cereals, orange juices, yogurt, and margarine also contain fortified vitamin D. It is important to note that other dairy products made from milk, such as cheese and ice cream, are not usually fortified. 5 Sunlight is another natural source for vitamin D. Ultraviolet B (UVB) radiation penetrates the skin and converts 7-dehydrocholesterol to previtamin D 3 which then becomes vitamin D 3. 5 Several environmental factors influence the amount of vitamin D people receive from sunlight including season, time of day, length of day, cloud cover, smog, skin melanin content, and sunscreen. 5 It has been suggested by some researchers that approximately 5-30 minutes of sun exposure between 10 AM to 3 PM at least twice a week to the face, arms, legs, or back without sunscreen will usually lead to sufficient vitamin D synthesis. 5 4

5 Vitamin D Supplementation According to the American Academy of Pediatrics, the following categories of children should receive daily supplementation of 400 IU: (1) breastfed infants (begin during first few days of life), (2) all nonbreastfed infants and children who are ingesting less than one liter of vitamin D fortified milk daily, (3) adolescents who do not get at least 400 IU through milk and foods, (4) children at risk of vitamin D deficiency, such as those with fat malabsorption and those taking chronic antiseizure medications. 4 Elderly patients are also at high risk for a vitamin D deficiency. Supplementation is warranted in those with malabsorption, chronic renal insufficiency, housebound patients, chronically ill patients and others with limited sun exposure. 1 Patients with renal disease have impaired conversion of vitamin D 3 to its active form, calcitriol. Such patients require supplementation with calcitriol or another active form of vitamin D analogue. 4 The recommended daily allowance of Vitamin D are presented in Table 2. Table 2. Recommeded Daily Allowances (RDAs) for Vitamin D 5 Age Male Female Pregnancy Lactation 0-12 months 400 IU 400 IU 1-13 years 600 IU 600 IU years 600 IU 600 IU 600 IU 600 IU years* 600 IU 600 IU 600 IU 600 IU years* 600 IU 600 IU >70 years* 800 IU 800 IU * National Osteoporosis Foundation recommends IU daily intake for adults under 50 and IU for older adults 4 Adverse reactions associated with vitamin D supplementation include weakness, headache, somnolence, nausea, vomiting, dry mouth, constipation, muscle pain, and bone pain. 6 Patients should discontinue treatment and notify their doctor if any of the above occur as well as vertigo, excessive thirst, excessive urine output, or weight loss, as these may be signs of overdose or toxicity. 6 Vitamin D-Drug/Food Interactions 5 The table below provides a list of common drug and food interactions with Vitamin D. Corticosteroids Impair vitamin D metabolism Orlistat (Xenical and Alli) Decreases vitamin D absorption Cholestyramine Decreases vitamin D absorption Phenobarbital and Phenytoin Increase metabolism of vitamin D Conclusion Calcium and vitamin D play an important role in cell function for people of all ages. As mentioned above, there are several sources of both calcium and vitamin D available in foods and supplements. The addition of calcium and vitamin D supplementation in patients who are not meeting their adequate daily intake is a valuable intervention to improve bone health and reduce fracture risk. 5

6 References 1. National Osteoporosis Foundation. Clinician s Guide to Prevention and Treatment of Osteoporosis. Washington, DC: National Osteoporosis Foundation; NIH Office of Dietary Supplements. Dietary Supplement Fact Sheet: Calcium. Accessed March 7, Straub DA. Calcium supplementation in clinical practice: a review of forms, doses, and indications. Nutr Clin Pract. 2007;22: Vitamin D dosing: an update. Pharmacists Letter/Prescriber s Letter. 2010;26(7): NIH Office of Dietary Supplements. Dietary Supplement Fact Sheet: Vitamin D. Accessed March 7, Facts & Comparisons. Facts & Comparisons Web site. com.ezproxy.samford.edu/. Accessed March 10,

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8 Calcium / Vitamin D Quiz 1. Which of the following is TRUE regarding recommended dietary allowances for calcium in female patients between the age of 51 and 70 years? a. 200 mg b. 700 mg c mg d mg 2. What is the maximum dose of elemental calcium that should be taken to ensure appropriate absorption? a. 200 mg b. 400 mg c. 500 mg d. 600 mg 3. Which of the following does NOT interact with calcium? a. Levothyroxine b. Tetracycline c. Corticosteroids d. All of the above products have the potential to interact with calcium. True/False 4. Calcium citrate contains 40% of elemental calcium. 5. Vitamin D is a fat-insoluble vitamin. 6. Approximately 5-30 minutes of sun exposure between 10 AM to 3 PM at least twice a week to the face, arm, legs, or back without sunscreen will usually lead to sufficient vitamin D synthesis. 7. How much vitamin D supplementation is recommended for pregnant patients between the ages of 19 to 50 years? a. 200 IU b. 400 IU c. 600 IU d. 800 IU 8. Which of the following agents can increase the metabolism of vitamin D? a. Corticosteroids b. Orlistat c. Cholestyramine d. Phenobarbital 9. Which of the following symptoms are consistent with an overdose of vitamin D? a. Nausea b. Excessive thirst c. Vomiting d. Bone pain 10. Which of the following represents a significant effect of vitamin D on the body? a. Cell growth b. Inflammation reduction c. Improving immune function d. All of the above 8