Nicotinic Acids a water-soluble vitamin is also known as vitamin B3, and niacinamide is its main form in animals.
The residents of areas where corn is the main food are prone to nicotinic acids deficiency. Although the nicotinic acids content of corn is higher than that of rice, the nicotinic acids in corn are of the bonded type, which is not easily absorbed and utilized by the body, but the addition of alkali can turn the bonded niacin into free niacin, which is easily utilized by the body.
Tuberculosis patients taking a large amount of long-term anti-tuberculosis drug isoniazid will affect the conversion of tryptophan into nicotinic acids, so it can also cause niacin deficiency.
When nicotinic acids are deficient, the synthesis of coenzyme I and coenzyme II in the body is blocked and certain physiological oxidative processes are impaired, resulting in the development of vitamin B3 deficiency - mange. The typical symptoms are dermatitis, diarrhea and dementia, the so-called "three D symptoms".
The side effects of excessive intake of nicotinic acids are mainly skin redness, eye discomfort, nausea and vomiting, hyperuricemia and abnormal glucose tolerance, etc. Long-term intake of large amounts can cause damage to the liver.
The reference intake of nicotinic acids should take into account energy consumption and protein intake. In addition to direct intake from food, niacin can also be converted in the body from tryptophan, with an average of 60 mg of tryptophan being converted to 1 mg of niacin. Therefore, the reference intake of vitamin B3 in the diet should be expressed as niacin equivalent (NE).
Niacin equivalent (mgNE) = niacin (mg) + 1/60 tryptophan (mg)
Nicotinic acids are widely found in a variety of plant and animal foods. Nicotinic acids are mainly present in plant foods and niacinamide in animal foods. Niacin and niacinamide are abundant in liver, kidney, lean poultry, fish, whole grains, and nuts. Niacin content in milk and eggs is low, but tryptophan content is high and can be converted to niacin in the body.