Niacin and Cardiovascular Health

Niacin is an important B vitamin with many health benefits. Because it is water soluble, it's important to maintain a continuous supply so that voiding the bladder doesn't deplete what the body has stored. Also known as vitamin B3, niacin is found in many foods but is also available as an over-the-counter supplement. In higher doses, it's available by prescription.

The most common use of niacin therapy is to improve the cholesterol levels in the body, and it has been used for this since the 1950s. It accomplishes this by increasing the level of desirable high-density lipoproteins (HDL) in the bloodstream, and it is more effective than statins. In fact, vitamin B3 can increase HDL up to 35 percent. When taken in conjunction with a statin, it also lowers undesirable low-density lipoproteins (LDL) and triglycerides, although this change is less dramatic than the change in HDL levels.

Improving cholesterol levels reduces the risk of heart disease and atherosclerosis, or hardening of the arteries. Unfortunately, the latter benefit may be negated by niacin's tendency to increase homocysteine levels.

Additional benefits

Adequate niacin is important for converting food to energy, and it's crucial to the health of the digestive and nervous systems. Anyone with a niacin deficiency is at risk for developing pellagra, a nutritional disease that develops when the body has an insufficient amount of either vitamin B3 or tryptophan. Symptoms of pellagra include skin disease, diarrhea, dementia, and depression. Fortunately, niacin deficiency is rare in developed countries; alcoholism is the primary cause in the United States.

Although there are other uses for niacin therapy, the benefits are not clear. Studies suggest niacin as a potential treatment for age-related macular degeneration, among other conditions. In addition, vitamin B3 may prevent Alzheimer's disease and diabetes, although more research is necessary to determine the validity of these claims.

Sources of niacin

The best way to get enough niacin is to eat a balanced diet, and many foods contain this essential vitamin. Some of the best sources are beef kidney and liver, beets, brewer's yeast, peanuts, salmon, sunflower seeds, swordfish, and tuna. Eggs, grains, green vegetables, legumes, and milk are also good sources. Some foods, such as poultry, red meat, eggs, and dairy, are beneficial because they contain tryptophan, which the body converts into niacin.

If you believe your diet is lacking in niacin, check first to see whether it's included in your multivitamin. If not, you can choose a niacin supplement from the options available over the counter. Be sure to ask for your doctor's advice beforehand; a supplement may not be necessary after all. Prescription brands include Niaspan, Niacor, and Slo-Niacin and must be prescribed by a doctor.

Side effects, contraindications, and drug interactions

Flushing is one of the most common side effects of niacin supplements. Although not serious, the annoyance factor sometimes prompts people to discontinue use. Flushing can be reduced by starting with a small dose of niacin and gradually increasing the dosage. Avoiding hot drinks and alcohol should help. In addition, some people find that taking an aspirin about 15 minutes before the niacin can reduce the flushing. Some prescription versions of niacin have a reduced risk of flushing; however, they carry a higher risk of stomach upset and liver irritation.

Other side effects include headache, anxiety, dizziness, itching, dry skin, mild stomach upset, nausea, vomiting, and diarrhea. Taking niacin with food may reduce the risk of upset stomach or ulcers.

Use of niacin supplements may result in increased blood sugar levels. Therefore, those with type 2 diabetes should use caution when adding niacin supplements to their regimen.

Some of the more serious side effects of niacin therapy include liver toxicity, stomach ulcers, lactic acidosis, myopathy, and arrhythmia. Liver function should be monitored while on niacin therapy. High doses of niacin may result in low blood pressure. In addition, problems associated with sustained-release niacin include clotting disorders.

It is possible to be allergic to niacin. Risks associated with an allergy to niacin include anaphylactic shock.

As with any dietary supplement, it's important to check with a doctor before adding niacin to your daily regimen.

Sources:

Mayo Clinic
University of Maryland Medical Center
Medline Plus