Niacinamide Clinical Evidence

Surjana D, et al. Oral nicotinamide reduces actinic keratoses in phase II double-blinded randomized controlled trials. 2012 May;132(5):1497-500.

Topic:

Can nicotinamide help reduce actinic keratoses (AKs)?

Background:

Nicotinamide has been shown to protect against skin cancer in animal research. Can it work in humans?

Study Type:

Human clinical intervention trial

Study Design:

Randomized, double-blind, placebo-controlled. Participants took nicotinamide either once or twice a day for 4 months. They underwent a skin examination at baseline and were encouraged to wear sunscreen throughout the study period. Researchers conducted additional skin examinations at 2 and 4 months to identify AKs and graph them on a body grid chart. At baseline and 2 months, researchers measured blood count, creatine, and liver function.

Dosage:

500 or 1,000 mg/day

Participants:

74 healthy, immune-competent volunteers with more than 4 AKs on the face, scalp, or arms

Results:

Participants in the 1,000 mg group experienced a 35% relative reduction in AK count at 4 months, with similar results at 2 months. Those in the 500 mg group experienced a 29% reduction at 4 months, with a smaller but significant reduction at 2 months. At baseline, 81% of participants in the high-dose group and 79% of those in the low-dose group had previous diagnosed skin cancers. During the study period, 11 volunteers in the placebo group developed 20 new cancers (basal cell carcinoma and squamous cell carcinoma), while 2 volunteers in the treatment group developed 4 new cancers (also basal cell carcinoma and squamous cell carcinoma). There were no significant side effects

Conclusions:

“The odds of developing at least one new skin cancer was significantly lower with nicotinamide…as was the rate of new skin cancers.”

Yiasamides E, et al. Oral nicotinamide protects against ultraviolet radiation-induced immunosuppression in humans. 2009 Jan;30(1):101-05.

Topic:

Can nicotinamide protect the skin against the immunosuppressive effects of UV radiation?

Background:

Even small amounts of UV radiation suppress cutaneous immunity, which protects the skin against skin cancer. Can nicotinamide help?

Study Type:

Human clinical intervention trial

Study Design: 

Randomized, double-blind, placebo-controlled crossover.  Participants took nicotinamide or placebo for 1 week. Areas of their backs were irradiated with low doses of UV radiation on 3 consecutive days, after which the researchers calculated immunosuppression at irradiated and unirradiated sites in both the control and placebo groups.

Dosage:

500 or 1,500 mg/day

Participants: 

Healthy volunteers

Results:

Researchers found significant evidence of immunosuppression in irradiated sites in the placebo group. Nicotinamide significantly reduced immunosuppression at both doses.

Conclusions:

“Oral nicotinamide at doses of either 1,500 or 500 mg daily, was well tolerated and significantly reduced UV immunosuppression with no immune effects in unirradiated skin. Oral nicotinamide is safe and inexpensive and looks promising as a chemopreventive supplement for reducing the immunosuppressive effects of sunlight.”

Nicotinamide’s mechanism of action is not yet completely understood. As a precursor of nicotinamide adenine dinucleotide (NAD), nicotinamide prevents the decline in cellular energy seen after exposure to UV radiation. This action could support cells’ DNA repair activity. Nicotinamide also helps prevent immunosuppression following exposure to the UV light that leaves cells vulnerable to cancer.