In "Textbook of Family Medicine," Baylor College of Medicine professor Robert Rakel reports certain benefits of multivitamins in the prevention of such diseases as cancer, osteoporosis and cardiovascular disorders. For instance, the niacin drugs Niacor or Niaspan act as reducers of bad cholesterol and boosters of good cholesterol. Niacin and its amide form niacinamide both make up vitamin B3. Although many people consider them equivalents, niacinamide has fewer therapeutic uses. Recommended dosages vary with age, gender and state of health.
Identification
Once absorbed in the body, dietary niacin is converted from its parent form, nicotinic acid, into its amide form, niacinamide. Niacinamide serves as a constituent of two coenzymes involved in tissue respiration, as well as the release of energy from fats, carbohydrates and proteins. According to Rx Med, your body can also produce about 1 mg of niacin from every 60 mg of dietary tryptophan it converts. Good food sources of niacin include animal proteins, beans, green vegetables, liver, mushrooms, peanuts, whole wheat, unpolished rice and enriched flours. Although milk and eggs do not contain niacin, they are rich in tryptophan.
Nutritional Requirements
Dosage recommendations for vitamins are referred to as reference daily intakes (RDI). According to the clinical reference MD Consult, adult and adolescent males should get 16 mg of niacinamide per day, while adolescent and adult females need 14 mg. If you're a pregnant or breast-feeding woman, the recommended dosages increase to 18 mg and 17 mg, respectively. Children between the ages of 9 and 13 require 12 mg per day, while those ages 4 to 8 need 8 mg. Younger children ages 1 to 3 need a daily dose of 6 mg. Although RDIs have not been established for infants, daily doses of 4 and 2 mg are considered adequate for seven to 12 month-old infants and those younger than six months, respectively.
Disease States
Certain disease states significantly raise niacinamide requirements. Pellagra, for instance, is a state of niacin deficiency that produces symptoms of diarrhea, dermatitis and dementia. Pellagra may result from a diet that is low in protein and niacin, isoniazid therapy or diseases that disrupt tryptophan utilization in your body. According to MD Consult, if you're an adult with manifestations of pellagra, you may need up to 500 mg of oral niacinamide per day, depending on the severity of your deficiency. In a clinical setting, you're more likely to receive intravenous or intramuscular doses. Children with pellagra may get up to 300 mg of niacinamide per day by slow IV infusion.
Considerations
Although niacin has known applications in the treatment of several diseases, there's an important distinction to make between its two forms, nicotinic acid and niacinamide. For instance, physicians at MD Consult describe nicotinic acid as an effective adjunct in the treatment of peripheral vascular disease, circulatory disorders and ringing in the ears, as well as high blood cholesterol and triglycerides. In contrast, niacinamide has not proven effective in any of those disorders.
Side Effects
Taking enough niacinamide or niacin to meet recommended daily values does not produce adverse effects, according to MD Consult. However, therapeutic levels and overdoses can cause flushing, itching, burning, tingling, stomach upset, dizziness, heart rate changes, fainting, headache, blurred vision and dental pain. Chronic overdosage can lead to gout, peptic ulcer, vision changes, high blood sugar and panic. The severity of niacin's side effects tends to increase when it's combined with other medications, particularly the cholesterol-lowering statins.
Tips
If you need to use niacin or niacinamide tablets, take them with food in order to reduce stomach upset. Physicians at the Mayo Clinic also suggest taking an antihistamine 15 minutes before a therapeutic dose of niacin to reduce side effects. Taking aspirin or non-steroidal anti-inflammatory drugs with niacin may specifically help reduce flushing.
References
- "Textbook of Family Medicine"; Robert E. Rakel, M.D.; 2007
- Mayo Clinic: Niacin & Niacinamide
- Rx Med: Niacin & Niacinamide
- MD Consult: Drugs & Monographs
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