| Food Acupuncture: Vitamin B3 |
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Food Acupuncture: Vitamins & MineralsSmall but significant: Tiny amounts big results Structuring/building/connecting/energizing/repairing/healing… The power of vitamins comes from the power of real food Vitamin B3 – water solubleVitamin B3, or niacin, is a very important water-soluble vitamin, also known as nicotinic acid. Niacin is used by the body to make a biologically active form, nicotinamide coenzyme (NAD), which is involved in all stages of energy creation. Over 400 enzymes require the niacin coenzymes. It is an interesting vitamin because, unlike other vitamins we can make it in our own bodies, therefore defying the rule that a vitamin cannot be made in the human body. Our bodies can take dietary tryptophan, an essential amino acid, and covert it into NAD, alas, fairly inefficiently. Although the term ‘niacin’ is often used to refer to nicotinic acid, other derivatives in the form of nicotinamides—which are all provided through diet—also contribute to the synthesis of NAD in the body. These are all, therefore, variants of the vitamin and are collectively referred to as niacin or vitamin B3. Sources of vitamin B3:Niacin is widely distributed in plant and animal foods. Good sources include yeast, meats (especially liver), poultry, eggs, tuna, salmon, milk, grains, legumes, cereal (especially fortified cereal), seeds, green leafy vegetables, green peas, peanuts, mushrooms, coffee and tea. Different foods vary in their vitamin B3 content. For example, 85 g of chicken, tuna, salmon, or beef provide 8.9, 8.6, 8.8, 8.5 mg of niacin respectively, whilst one cup of unfortfified cereal, enriched pasta, lentils, beans, or coffee will provide 5-7, 2, 2, 0.8, 2 mg of niacin, respectively.
It is possible to maintain adequate niacin status on a high protein diet, e.g. a protein intake of 100 g/day). Functions:Niacin is an essential nutrient, vitally important to all forms of life which derive most of their energy from chemical reactions. Nicotinamide coenzyme plays a critical role in the preparation of fats, carbohydrates, proteins and alcohol to burn in the cells. In effect, NAD’s main function is helping in the breaking down, or catabolism, and conversion of food into energy, in collaboration with other B vitamins, thiamine, riboflavin, pantothenic acid and biotin. It is equally essential for healthy skin, blood cells and NAD also serves in the synthesis of e.g, cholesterol, bile acids, and steroid hormones. Absorption:For intestinal absorption niacin needs to be converted into nicotinamide and nicotinic acid, two different forms of vitamin B3. Absorbed niacin is rapidly taken up by the liver, kidneys, and red blood cells, and concentrated in tissues with high metabolic activities such as muscles or the liver.
Vitamin B3 deficiency:Fortunately, niacin deficiency is not too common nowadays if enough wholegrain food is consumed. Deficiency may result from inadequate dietary intake of nicotinic acid, defective tryptophan absorption, metabolic disorders, and/or the long-term use of chemotherapeutic treatments, and poor bio-availability from grains. In mature cereal grains such as corn and wheat, niacin may be bound to sugar molecules which significantly decrease its bio-availability. Niacin deficiency, is often associated with a poor diet, and is often observed in the homeless population, in individuals suffering from anorexia nervosa or obesity, and in consumers of diets high in maize and poor in animal protein. Similarly, deficiencies of other B vitamins and/or some trace minerals and malabsorptive disorders such as Crohn’s disease, may aggravate niacin deficiency. Special groups: Symptoms of deficiency: Early records of pellagra followed the widespread cultivation of corn in Europe in the 1700s. The disease is generally associated with poorer social classes, and was common in parts of United States during the early twentieth century where income was low and corn products were a major dietary staple. The technique of enriching processed flour with niacin, along with the other B vitamins, has virtually eradicated pellagra in most countries, especially in developed countries. Supplements:Niacin supplements are available as nicotinamide or nicotinic acid. A common side effect of nicotinic acid is flushing, which may occur at doses as low as 30mg/day. Nicotinamide is generally better tolerated (see toxicity section.) Toxicity:Nicotinic acid is likely to be safe for most people when taken by mouth from a supplement. A common minor side effect of nicotinic acid is a flushing reaction. This might cause burning, tingling, severe, itching, and especially redness of the face, arms and chest. Usually, this reaction disappears as the body gets used to the medication. Alcohol can make the flushing reaction worse and might increase the chance of having liver damage, it is therefore advised to avoid large amounts of alcohol while taking niacin. Other common side effects of nicotinic acid include gastrointestinal disturbances, such as nausea and vomiting, and transient episodes of low blood pressure and headache have also been reported. Liver damage has been observed at intakes as low as 750 mg/day of nicotinic acid. Although nicotinamide is generally better tolerated than nicotinic acid, stomach upset, gas, and signs of liver toxicity have been observed at very high doses (?10 g/day). Tolerable upper intake level: Although flushing from nicotinamide is rare the “tolerable upper intake level” for both nicotinamide and nicotinic acid is set by the US Food and Nutrition Board at 35mg/day in adults to avoid the adverse effect of flushing, though the recommended dietary allowance for niacin is 16mg/day for adult males and 13mg/day for females. However, in a recent US National Health and Nutrition Examination Survey 15.8% of children and adolescents and 8.5% of adults were found to have total usual intakes exceeding the upper level. Drug Interactions: Adverse effects of large doses of nicotinic acid may be exacerbated by the concomitant use of certain medications. For example, the risk of liver toxicity observed with nicotinic acid might be increased by drugs like paracetamol, amiodarone (Cordarone), or Tegretol. Sustained-release niacin preparations seem to have the greatest risk. Large doses of nicotinic acid may reduce uric acid excretion, thereby opposing the action of drugs used to treat gout, such as Allopurinol and may also decrease the effectiveness of diabetes medications. Estrogen and estrogen-containing oral contraceptives increase the efficiency of niacin synthesis from tryptophan, resulting in a decreased dietary requirement for niacin. Disease treatment: Return to the list of B vitamins. Return to the overall list of vitamins and minerals.
Related material Read the first article in the series, on what vitamins are and why we need them. Read the second article in the series on how vitamins work. Read the third article in the series on supplements. Read the Recommended Dietary Allowance for vitamins and minerals Read how supplements are regulated. In A ticking bomb, Professor Alpar discussed the critical situation in antibiotics with the late Professor Vivian Moses. A brief biography of Professor Alpar can be found here.
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