Vitamin Watch: What Does B3 Do?

Vitamin B3, also known as niacin, is an essential nutrient for humans. It helps major organs, including the brain, skin, and gut, to function and help DNA repair itself.

Recommended daily intake of vitamin B3 is between 2-12 milligrams (mg) a day for children, 14 mg a day for women, 16 mg a day for men. Women who are pregnant or breast-feeding should get 18 mg and 17 mg a day respectively.

People who consume too much niacin often experience flushing of the skin, which typically subsides in less than an hour.

Natural Sources of Vitamin B3

Niacin is found naturally in many food sources, including in fruits, vegetables, meat, and beer. Yes, beer! Brewer’s yeast is one of the most abundant sources of niacine. A pint of beer contains about 6 mg of vitamin B3, but less if it’s filtered. This means that all it takes to meet your daily requirement is putting back three beers a day.

Because your doctor may not approve of that specific approach for obtaining your vitamins, you could also try these other niacin-rich foods:

  • Vegemite and Marmite
  • liver, heart, and kidney meats
  • chicken breast, fish, venison, and beef
  • dates
  • avocados
  • nuts
  • whole-grain bread products
  • shiitake mushrooms

Organ meats are one of the easiest ways to get a lot of vitamin B3, but vegetarians and vegans can find it in the aforementioned fruits and vegetables, as well as in peanut butter, tofu, and the nutritional drink Ovaltine.

Niacin for the Heart

The prevailing thought in the medical community is that vitamin B3 can help reduce the risk of cardiovascular disease. It does this by boosting the amount of high-density lipoproteins (HDL, or “good” cholesterol) and also lowering the levels of harmful cholesterol (LDL, or “bad cholesterol”) that can lead to heart attacks or strokes.

The Mayo Clinic warns that niacin isn’t for everyone, namely people who are already on medications to lower their cholesterol.

While vitamin B3 is available in foods, it also comes in drug form. Niacor and Niaspan are approved for people with a vitamin B3 deficiency or to treat high cholesterol levels.

Other Possible Benefits

While some people believe that niacin may help ward off types of diabetes, research remains inconclusive.

Increased vitamin B3 intake may be beneficial for people with compromised immune systems who are at a greater risk for cardiovascular events. For instance, people undergoing chemotherapy and people with HIV.

As niacin plays a crucial role in making sure that major organ function properly, people with niacin deficiency often experience systemic and painful side effects.

Symptoms of Deficiency

People with low levels of vitamin B3 can develop pellagra, a condition trademarked by “the four Ds”: dermatitis, dementia, diarrhea, and death. It can be treated with nicotinamide, or niacinamide, a form of niacin that’s less toxic in higher doses than niacin. 

While pellagra is rare in more developed countries, less extreme forms of vitamin B3 deficiency include feeling lethargic, nauseous, and experience anemia or lesions on the skin or around the mouth. Deficiency can also lead to extreme sunlight sensitivity.

Symptoms of Excessive Niacin

Too much vitamin B3 can be toxic. Patients should discuss using it in supplement form with their doctors first. There may be complications, especially if you are taking other medications. The primary concern with too much niacin is inflammation of the liver. For this reason, people who take niacin to treat high cholesterol often have their liver enzymes checked when beginning therapy.