Vitamin B3 (a.k.a. Niacin and its no flush cousin Niacinamide) is the only essential vitamin that the body can make. Derived from the amino acid tryptophan, under full-blown deficiency conditions, the amino acid will be redirected from its normal role as a precursor to serotonin to assure an effective niacin supply.

Still, if not enough is available in the diet, health will suffer and pellegra, full-blown niacin deficiency disease, can ensue. The symptoms of pellegra known as the 4D’s: diarrhea, dermatitis, dementia and death. While these days, it’s a rare diagnosis, it’s likely that sub-acute pellegra, manifesting as digestive issues, rashes and cognitive decline, occur more often than is recognized.

Niacin plays an important role in psychological health. It’s been used to treat schizophrenia. Some researchers believe that reliance on an addiction to nicotine, which has some biochemical similarities to niacin, may be the result of an ineffective attempt at coping with B3 deficiency induced stress, depression and anxiety. The nutrient has even been used to treat insomnia.

Niacin also plays a key role in fat metabolism and its actions help keep arteries clear of inflammatory blood fats that clog arteries and exacerbate heart disease. What’s more, vitamin B3 can reduce fat deposits, making supplementation valuable for patients dealing with lipomas, obesity and fatty liver disease. When used directly on the skin, both niacin and niacinamide can provide topical benefits, helping clear acne blemishes, reduce oiliness and lighten dark spots.