Vitamin B3 (nicotinamide) and skin cancer

Nicotinamide tablets

Vitamin B3 (nicotinamide) can be an effective way of treating and preventing solar keratoses (“sun spots”). There is also evidence that vitamin B3 can prevent common skin cancers.

How does it work?

Exposure to ultraviolet (UV) radiation in sunlight increases the risk of skin cancer by

  • damaging the DNA in skin cells, and
  • reducing the immune system’s anti-cancer response.

The immune response can be affected by a very small amount of UV. On a sunny day in summer, the immune system’s anti-cancer response could be suppressed in only six minutes. Vitamin B3 partially protects against this immune system suppression.

It does not prevent damage to the skin cells caused by UV radiation, so it’s still very important to stay sun smart and avoid excessive exposure to sunlight when the UV index is greater than 3.

Vitamin B3 is present in very small amounts in yeast, meat, fish, nuts, legumes and some mushrooms. There is not enough vitamin B3 in these foods to effectively reduce skin cancer risk.

How to take vitamin B3

The most effective dose is nicotinamide 500mg twice daily, although once daily dosing is partially effective.

Please note:

  • Multivitamins and B-complex preparations do not contain adequate vitamin B3.
  • It’s important to take the correct form of vitamin B3. Make sure the tablets are nicotinamide and not nicotinic acid/niacin, which may cause side effects.
  • Nicotinamide comes in 500mg tablets. Take two per day. If you have purchased 100mg tablets, they are possibly the wrong formulation. Make sure they are nicotinamide before you take them.

In Australia, nicotinamide is available in products from Blackmores (“Insolar”), Herbs of Gold and Nature’s Own. Typically, it costs less than $20 for a month’s supply.

As with most vitamins, vitamin B3 works while it is being taken, and its effects wear off when stopped. In other words, it needs to be taken indefinitely.

Vitamin B3 is also effective when used directly on the skin. It is available in some sunscreens and skin creams.

How effective is vitamin B3?

Non-melanoma skin cancers and solar keratoses

Research has shown that vitamin B3 (nicotinamide) 500-1000mg per day, taken orally, was effective in a group of patients with significantly sun damaged skin. The observed effects were:

  • Solar keratoses were reduced by about a quarter, and
  • Development of new basal cell carcinomas and squamous cell carcinomas was reduced by about 23 (but in an earlier study, up to 75) per cent.

The maximum effect was achieved after several months of taking nicotinamide. Further research is underway to determine the benefits of vitamin B3 in people with different skin types.

Vitamin B3 is not a cure for solar keratoses. For the best results, people with solar keratoses should use one of the other treatments such as a prescription cream or cryotherapy (freezing) in conjunction with vitamin B3.


The action of vitamin B on skin cells could theoretically help prevent melanoma. The research done so far has focused on very common skin cancers over one year. To get significant results about melanoma, which is more uncommon, researchers would have to observe a larger group of people for a longer period. This type of study is planned.

There is no current evidence that nicotinamide reduces melanoma risk.

Side effects

Side effects from nicotinamide are uncommon at the recommended dosage of 500mg twice daily. A very small number of people experience an upset stomach, nausea or diarrhoea. This usually settles if it is taken with meals. Vitamin B3 taken as niacin/nicotinic acid commonly causes unpleasant hot flushes.


Vitamin B3 does not protect against sunburn. It is not a substitute for sunscreen and other protective measures to reduce UV exposure.