NADH—the active form of vitamin B3 in the body—has been shown to reduce symptoms and improve brain function in people with Parkinson's disease.
Drug therapy for Parkinson's disease has been reported to deplete vitamin B3 in humans. Vitamin B3 may be needed to decrease SAMe levels, and in so doing, may possibly help people with Parkinson's disease. However, the two main forms of vitamin B3, niacin and niacinamide, when taken in combination with L-dopa, have demonstrated no benefit for people with Parkinson's disease. Nicotinamide adenine dinucleotide (NADH)—the active form of vitamin B3 in the body—effectively raises the level of dopamine in the brain, making it potentially useful in the treatment of people with Parkinson's disease. In preliminary research, NADH supplementation reduced symptoms and improved brain function in people with Parkinson's disease. One researcher has recommended 5 mg taken twice per day for people with Parkinson's disease. However, one small, double-blind, short-term trial using injections of NADH found no significant effects.