ad been reported even from large doses of riboflavin However, one new study indicated that high consumption of vitamin B2 may increase the risk of stomach cancer. (In the same study, vitamins B1, B3, and B6 were protective).Deficiencies and Toxicity of Vitamin B3 (Niacin)Niacin, also known as nicotinic acid, helps break down blood sugar for energy and also acts as a vasodilator, widening blood vessels and increasing blood flow. Dietary sources are mackerel, swordfish, chicken, veal, dried fortified cereals, pork, salmon, and beef liver. Current DRI recommendations are 20 mg. This vitamin may be prescribed for improving cholesterol levels, but supplements are unnecessary in people with normal health and diets. A deficiency of niacin causes pellagra; symptoms can include eczema, intestinal and stomach distress, depression, headache, thinning of the hair, and excess saliva production. Anemia may occur, although this is probably due to an accompanying deficiency in folic acid (see Folic Acid, below). Even mildly high doses of niacin can cause hot flushing of the face and shoulders, headache, itchiness, and stomach problems. Some report heart disturbances and temporarily lowered blood pressure. Large doses may produce ulcers, gout, diabetes, and liver damage, which are usually reversed when high doses are discontinued.Deficiencies and Toxicity of Vitamin B5 (Pantothenic Acid)Pantothenic acid, like many B vitamins, plays a wide role in the body, including metabolism of fats, carbohydrates, and proteins, as well as production of steroid hormones and other important chemicals. Dietary sources are whole grains, beans, milk, eggs, and liver. Recommended adequate intake (AI) is 4 to 7 mg. Supplements are unnecessary in people with normal health and diets. Deficiency is unlikely except in company with other B vitamin deficiencies. Symptoms include abdominal distress, burning sensation in the heels, and sleep problems. Although no toxicity has been ...
