What it is
Vitamin B3 is a water-soluble vitamin.
What it does
Vitamin B3 is the primary component of the coenzyme NAD, which assists in over 400 different chemical reactions in the body.
The recommended intake for vitamin B3 is 16mg per day for men and 14mg per day for women who aren’t pregnant or lactating. Pregnancy and lactation can increase intake requirements for vitamin B3.
There is no suggested upper limit for vitamin B3 intake from natural dietary sources of vitamin B3, but most health authorities recommend consuming no more than 35mg of synthetic vitamin B3 per day from fortified foods and supplements.
These intake recommendations are all based on niacin equivalents, which account for niacin itself, along with tryptophan, nicotinamide, and nicotinic acid.
Likelihood of tracking completeness: Very low
Vitamin B3 is not a nutrient that food manufacturers are required to disclose on nutrition labels. The vast majority of food and beverage manufacturers do not voluntarily list vitamin B3 content on nutrition labels, so most branded products in the MacroFactor database lack information on vitamin B3. So, if you’d like to accurately track your vitamin B3 intake, you’ll need to make a point of mostly tracking “common foods,” which come from research-grade databases that have full nutrient reporting.
For more on when you can track using branded foods versus common foods when you’re trying to accurately monitor your intake of particular nutrients, you should check out this article.
Likelihood of insufficient intake: Very low
Most adults in developed countries consume adequate amounts of vitamin B3.
For more on nutrients with a greater likelihood of insufficient or excessive intake, you should check out this article.
Signs of deficiency
Vitamin B3 deficiency results in a disease called pellagra. Pellagra has wide-ranging symptoms, including skin discoloration, a bright red tongue, vomiting, constipation or diarrhea, and a variety of cognitive and neurological symptoms. Advanced pellagra can be fatal.
Some of the best sources of niacin include mushrooms, tuna, yeast and yeast-derived products (like nutritional yeast and marmite), salmon, liver, broccoli raab, poultry, tomatillo, and asparagus.
If you’d like to learn more about micronutrients generally, there’s a five-part series on the MacroFactor website you might enjoy.