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Vitamin B - What you need to know The B Group of Vitamins is made up of 8 distinct compounds. Thiamin (B1) Thiamin occurs in most plant and animal tissue playing an essential part in supplying energy to the tissue through carbohydrate metabolism and through metabolic links between carbohydrate, fat and protein metabolism. The body content of Thiamin is about 30mg. Excess consumption of it is excreted. Thiamin can be found in many foods including large amounts in liver, pork, brown rice, cereals and beans. Riboflavin (B2) Ribflavin plays a complex and essential role in a wide variety of cellular processes. It is essential to the proper and efficient metabolism of all food. It is found in high quantities in milk and cheese, leaf vegetables, liver, kidneys, legumes, tomatoes, mushrooms and almonds. Exposure to light destroys riboflavin. Although riboflavin is found in a wide variety of foods, it is so important to healthy functioning that it is often supplemented artificially. Recommended dietary intake of Riboflavin at least 1.1mg a day up to 1.6mg per day for pregnant women. Excess Riboflavin is simply excreted. Niacin (B3) Niacin is the generic term for a few compounds in the B3 category. Niacin is involved in DNA repair and other metabolic roles within living cells. It is also required for production of steroid hormones in the adrenal gland. It has been shown to increase levels of HDL (good cholesterol). Daily recommended doses are between 2mg (for young children) up to 14mg for women, 16mg for men and 18mg for pregnant women. Upper limits for adults are 35mg per day. Excess use can cause flushing. Niacin can be found in a wide variety of meats and vegetables including: chicken, beef, fish, eggs, avocadoes, tomatoes, broccoli, carrots, asparagus, nuts, whole grains, mushrooms and soy. Mild niacin deficiency can cause a decreased metabolism. This obviously means that for those watching their weight, they should be sure to get enough niacin, but NOT to overdue it. Pantothenic Acid (B5) Vitamin B5 is required by the body for protein and carboohydrate metabolism and is also used in cholesterol metabolism and hormone production. It is found in small quantities in nearly all foods. It is found in large quantities in grain cereals, legumes, eggs, meat, avocado and yoghurt. Whole grains are a useful source of B5 but milling can destroy much of the B5 which is found in the outer layers. This is another of those reasons why whole grains are better for you. Recommended intake of B5 is from 1.7mg for infants up to 6-7mg for pregnant and lactating women. Adult men and women require 5mg per day. B5 supplementation may have benefits in reducing lactic acid build up in muscles and reduced morning stiffness. A standard Berocca supplement contains 23mg of B5. There is no upper limit or toxicity limit for B5 established. It does not appear to be a vitamin that you can overintake, but if supplementing, there may be little benefit in excess doses making greatly increased doses a waste of money. Pyridoxine (B6) Pyridoxine is one of the B6 compounds, so it is something of a generic term. Vitamin B6 is essential to amino acid metabolism making it very important for athletes but obviously of great value to all. It plays a significant role in many other aspects of human functioning including fat metabolism, histamine synthesis, neurotransmitter synthesis and gene expression. Recommended guidelines for B6 are from 0.1mg per day to 2mg for pregnant and lactating women. Adult men require 1.3mg rising to 1.7mg at 50 years of age. Adult women require 1.3mg rising to 1.5mg at 50 years of age. Vitamin B6 can be found in meats, whole grains, legumes, vegetables, nuts and bananas. Cooking and storage of foods can cause up to 50% losses in this vitamin. Excess consumption has not been recorded from normal dietary intake and in Australia an upper limit of 50mg per day has been suggested. The US FDA sets the limit at 100mg. A typical Berocca contains just 10mg and given the required dosages are as low as they are, toxicity from excess intake is highly unlikely. Biotin (B7) Biotin is sometimes referred to as Vitamin H or Coenzyme R. Biotin is necessary for cell growth, production of fatty acids and energy metabolism. Biotin is found in high quantities in swiss chard, raw egg yolk, liver and peanuts. But it is only required in small doses and it is also found in low quantities in wide range of foods such that deficiency is rare. In a strange twist, a compound in raw egg whites acts to limit the bio-availability of Biotin in egg yolks. Pregnant women run a risk of having a Biotin deficiency and careful supplementation under medical supervision may be recommended. Biotin deficiency can cause hair loss and brittle nails. Folic Acid (B9) Folic Acid, or Folate, is needed to form red blood cells. It is essential to the development of the foetal nervous system (why it is so important for pregnant women) as well as DNA synthesis and cell growth. Folate can be found in high quantities in green leafy vegetables, legumes, seeds, poultry, eggs, cereals and citrus fruits. Many types of grains including breakfast cereals are now fortified with folic acid. The daily recommended dose for healthy adults is 400mg with an upper limit of 800mg. Intake above 1000mg per day may lead to malaise and irritability. Cobalamins (B12) Vitamin B12 is used to help maintain and support the myelin surrounding nerve cells, mental ability and red blood formation. It also plays a role in metabolic functioning of amino acids to produce energy. Folate and Vitamin B12 work together. Daily intakes for B12 are 2-3 mcg in healthy adults. There is insufficient information to conclude that there is a toxic level of B12 but it seems highly unlikely from dietary sources. Vitamin B12 can be found in high quantities in liver, meat, milk, cheese and eggs. Vitamin B12 deficiency can be a real problem for vegans. It is recommended thast vegans consume cereals fortified with B12 or take a supplement of B12. A standard Berocca contains 10mcg of Vitamin B12, which is of course plenty when compared with dietary minimum requirements. |