Some people who try a vegetarian or vegan diet soon revert back to meat and dairy products, complaining that they didn't feel healthy. This is most likely because they were lacking in some essential nutrients because of an incomplete or erroneous understanding of human nutrition. When opting out of the standard Western diet, one must be careful to fully understand the alternatives.
The article Staying A Healthy Vegan and the Vegan Society's website provide good sound advice on how to avoid dietary deficiencies. For instance, there are no reliable, unfortified plant sources of vitamin B12; therefore fortified foods and/or supplements are necessary for the optimal health of vegans, to provide either 3 micrograms of B12 twice/thrice a day, or 10 mcg once a day, or a weekly supplement providing at least 2000 mcg. (Absorption is best for lower amounts more regularly.) Unlike most water-soluble vitamins, excess B12 is stored in the liver for future use, so people with large built-up stocks can survive for a few years with no new intake, only then to become seriously deficient. If not taking meat or dairy products, then fortified foods or supplements of B12 are essential.
The "new" vegetarian, who has recently given up some or all animal products, may go into negative mineral balance. If mineral absorption mechanisms need time to adjust to reduced intake of minerals (especially [the plant form of iron]), and increased [fiber] then a modest supplement might ease this transition. Iron, zinc and calcium would be affected. The vegetarian who progresses to veganism certainly requires additional vitamin B12, and iodine and riboflavin are to be recommended as well.
- Draper A, Lewis J, Malhotra N, Wheeler E - British Journal of Nutrition 1993 Jan;69(1):3-19
I have been taking Solgar Vegetarian Multiple vitamin supplements for some time now; they are not strictly vegan, as they include beta-carotene derived from wool, but then so does my sweater. Vegans should ensure that they take supplements of at least vitamins B12 and D, iodine, calcium, omega-3 fats and iron.
Many people needlessly worry that a Vegan diet cannot provide enough protein, without realising that proteins are found in most foods to some degree, and in plentiful amounts in nuts, seeds, lentils, beans and brown rice. The official daily recommendation for protein has gone down from the 150 grams recommended twenty years ago to only 45 grams today, mainly because reliable worldwide research has shown that we do not need so much. Many meat-eaters consume too much protein.
If you have to take antibiotics to kill some infection, they may invariably also kill off the friendly bacteria found in the healthy gut that aids digestion. It is a good idea when on such medication to take supplements of Lactobacillus acidophilus to replace the loss. Alternatively, for those who take dairy products, acidophilus is found in live yoghurt (check the label).
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© copyright Malcolm Smith 2003-01-06 - last updated 2004-02-01 - links verified 2004-02-01