What happens if you don't get enough vitamin B3?

The recommended daily allowance of niacin is 2-12 mg a day for children, 14 mg a day for women, 16 mg a day for men, and 18 mg a day for pregnant or breast-feeding women.

Pellagra

Pellagra is a vitamin deficiency disease caused by dietary lack of niacin (vitamin B3) and protein, especially proteins containing the essential amino acid tryptophan. Because tryptophan can be converted into niacin, foods with tryptophan but without niacin, such as milk, prevent pellagra. However, if dietary tryptophan is diverted into protein production, niacin deficiency may still result.

Tryptophan is an essential amino acid found in meat, poultry, fish, and eggs. So, if your diet contains these foods, your need for niacin from other sources will be reduced.

Symptoms

The symptoms of pellagra include:

high sensitivity to sunlight
aggression
dermatitis
smooth, beefy red glossitis
red skin lesions
insomnia
weakness
mental confusion
diarrhea
eventually dementia

The main results of pellagra can easily be remembered as "the four D's": diarrhea, dermatitis, dementia, and death.

Pellagra can be common in people who obtain most of their food energy from maize, since untreated corn is a poor source of niacin (vitamin B3). Corn is also a poor source of tryptophan. This disease can be common among people who live in rural South America where corn is a staple. The symptoms usually appear during spring, increase in the summer due to greater sun exposure, and return the following spring.

It is also one of several diseases of malnutrition common in Africa, and was endemic in the poorer states of the U.S. south like Mississippi and Alabama as well as among the inmates of jails and orphanages, where it was studied by Joseph Goldberger who conducted experiments in the penal colony in Rankin. Also found in cases of chronic alcoholism.

Untreated, the disease can kill within four or five years.

Niacin Treatment

Pellagra can be treated by treatment with niacin (usually as niacinamide). The frequency and amount of niacinamide administered depends on the degree to which the condition has progressed.

A mild Vitamin B3 deficiency slows down the metabolism, causing decreased tolerance to cold.