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1 Lauren Arnett KNH Niacin Medical Nutrition Therapy Nutrient 1. What is the nutrient? The nutrient is niacin which is a water soluble type B vitamin. Niacin aids in the digestive system, skin and nerve function as well as the conversion of food to energy for the body from carbohydrates. Niacin can be reached solely through dietary sources. Typically, people in third world countries have niacin deficiency and people in the US do not; however, when they do it is usually caused by alcoholism. Niacin is mainly used for high cholesterol, but it can also be used for acne, memory loss, arthritis and circulation problems What is the RDA/DRI for the nutrient? Factors that affect the amount of niacin include age, gender, and pregnancy. The Recommended Dietary Allowance (RDA) is the average daily intake that is enough to meet the nutrient requirements of nearly all (97-98%) healthy people. The daily recommended intakes are listed below in the chart.

2 ion/dris/rda%20and%20ais_vitamin%20and%20elements.pdf 3. How is the nutrient metabolized? Niacin is well absorbed when taken by mouth due to being water-soluble. When taken in a physiologic dose it is metabolized in the liver into niacinamide, and when a therapeutic dose is taken only a portion is converted. It is widely distributed throughout the body and eventually gets excreted through the urine. People with liver problems need to be careful when consuming high doses of niacin because this can cause even more problems to arise. Niacin is dose rate specific and one pathway is through a simple conjugation step with glycine. Another pathway forms nicotinamide adenine dinucleotide. It is further metabolized into other compounds and there is a nonlinear relationship between niacin dose and plasma concentrations after multiple dose administration What are food sources of the nutrient? Food sources of niacin include dairy products, eggs, enriched breads and cereals, fish, lean meats, legumes, nuts and poultry. Specifically, beets, beef liver, sunflower seeds, and peanuts are great sources. Food Serving Niacin (mg) Chicken (light meat) 3 ounces* (cooked without skin) Tuna (light, canned, packed in water) 3 ounces Turkey (light meat) 3 ounces (cooked without skin) 10.0 Salmon (chinook) 3 ounces (cooked) 8.5 Beef (90% lean) 3 ounces (cooked) Cereal (unfortified) 1 cup 5-7 Cereal (fortified) 1 cup Peanuts 1 ounce (dry-roasted) 3.8 Pasta (enriched) 1 cup (cooked) Lentils 1 cup (cooked) 2.1 Lima beans 1 cup (cooked) Bread (whole-wheat) 1 slice 1.3 Coffee (brewed) 1 cup 0.5

3 What disease states alter the nutrients metabolism? Niacin is affected by diseases states such as defective tryptophan absorption, long term use of chemotherapeutic treatment, people with Hartnups disease, increased serotonin levels, drugs given for Parkinson s disease, people with chronic alcoholism and with HIV What are the tests or procedures to assess the nutrient level in the body? A niacin skin flush test can be conducted as well as a urine test to assess niacin metabolites in the urine. 7. What is the drug nutrient interactions? These are a list of some of the drug interactions as specified by the University of Maryland Medical Center. Antibiotics, Tetracycline -- Niacin should not be taken at the same time as the antibiotic tetracycline because it interferes with the absorption and effectiveness of this medication. All vitamin B complex supplements act in this way and should be taken at different times from tetracycline. Aspirin -- Taking aspirin before taking niacin may reduce flushing from niacin, but take it only under your doctor's supervision. Anti-seizure Medications -- Phenytoin (Dilantin) and valproic acid (Depakote) may cause niacin deficiency in some people. Taking niacin with carbamazepine (Tegretol) or mysoline (Primidone) may increase levels of these medications in the body. Anticoagulants (blood thinners) -- Niacin may make the effects of these medications stronger, increasing the risk of bleeding. Blood Pressure Medications, Alpha-blockers -- Niacin can make the effects of medications taken to lower blood pressure stronger, leading to the risk of low blood pressure. Cholesterol-lowering Medications -- Niacin binds the cholesterol lowering medications known as bile-acid sequestrants and may make them less effective. For this reason, niacin and these medications should be taken at different times of the day. Bile-acid sequestrants include colestipol (Colestid), colesevelam (Welchol), and cholestyramine (Questran). Statins -- Some scientific evidence suggests that taking niacin with simvastatin (Zocor) appears to slow down the progression of heart disease. However, the combination may also increase the likelihood for serious side effects, such as muscle inflammation or liver damage. Diabetes Medications -- Niacin may increase blood sugar levels. People taking insulin, metformin (Glucophage), glyburide (Dibeta, Micronase), glipizide (Glucotrol), or other

4 medications used to treat high blood glucose levels should monitor their blood sugar levels closely when taking niacin supplements. Isoniazid (INH) -- INH, a medication used to treat tuberculosis, may cause a niacin deficiency. Nicotine Patches -- Using nicotine patches with niacin may worsen or increase the risk of flushing associated with niacin. These are a list of medications that may lower levels of niacin in the body: Azathioprine (Imuran) Chloramphenicol (Chloromycetin) Cycloserine (Seromycin) Fluorouracil Levodopa and carbidopa Mercaptopurine (Purinethol) University of Maryland Medical. Center niacin#ixzz2zk4w434c 8. How is the nutrient measured? Niacin is measured by the urinary excretion of niacin metabolites. Urine is tested to help tell niacin levels through niacin elimination What is the Upper Tolerable Limits? This is based on skin flushing which is a common side effect of niacin.

5 10.What are the physical signs of deficiency? Symptoms of deficiency include indigestion, fatigue, canker sores, vomiting, depression, and if niacin deficiency because extremely bad then pellagra may occur. Pellagra includes signs of scaly skin, and diarrhea. Other signs such as a swollen red tongue may present What are physical signs of toxicity? Signs of niacin toxicity include severe skin flushing, rapid heart beat, itching, nausea and vomiting, abdominal pain, diarrhea, and severe liver damage. More severely niacin overdose can lead to hepatotoxicity. This occurs when doses above 500mg are taken which is rare.