The niacin form of vitamin B3 is used by doctors to lower cholesterol levels, but niacin also lowers TG levels.¹ The amount of niacin needed to achieve worthwhile reductions in cholesterol and TG levels is several grams per day. Such quantities can cause side effects, including potential damage to the liver, and should not be taken without the supervision of a doctor. Some doctors recommend inositol hexaniacinate (a special form of vitamin B3) as an alternative to niacin. A typical amount recommended is 500 mg three times per day.^2,3 This form of vitamin B3 does not typically cause a skin flush and is said to be safer for the liver than niacin. However, the alleged safety advantage of inositol hexaniacinate needs to be confirmed by additional clinical trials. Moreover, it is not clear whether inositol hexaniacinate is as effective as niacin at lowering cholesterol and TG levels.

In the 1940s and 1950s, one doctor reported that supplemental niacinamide (a form of vitamin B3) increased joint mobility, improved muscle strength, and decreased fatigue in people with osteoarthritis.^4,5,6 In the 1990s, a double-blind trial confirmed a reduction in symptoms from niacinamide within 12 weeks of beginning supplementation.⁷ Although amounts used have varied from trial to trial, many doctors recommend 250 to 500 mg of niacinamide four or more times per day (with the higher amounts reserved for people with more advanced arthritis). The mechanism by which niacinamide reduces symptoms is not known.