|Dosage Doses advised are deliberately on the safe side and may not be high enough to give benefit, but it is recommended that higher dosages should only be taken under the care of a practitioner experienced in nutritional medicine.
Side effects refer to effects of much larger doses on the whole than those recommended in this book.
Are supplements necessary?
Supplements should not be needed provided that one is eating a good, well-balanced, wholegrain diet with plenty of raw, organically grown vegetables and fruit. There is concern, however, that certain agricultural processes have led to losses of specific nutrients in the food chain. There are also specific times when supplementation may be required, such as when taking certain drugs, oral contraceptive pills, during pregnancy and while lactating, during and after weight loss, and if you are elderly. If you feel that you are generally under par, i.e. physically low in energy or mentally lethargic, there is no harm in taking a multivitamin and mineral supplement for a month. We recommend that you take one that is not time-released, which contains less than 25 mg of each of the major B vitamins (B1, B5, B6) and has a Zinc to Copper ratio of not less than 14 to 1. Choose one that is free of additives and colourings. Children's chewable vitamins and minerals are available.
The quality of supplements
Nutritional supplements are available from one of four sources: chemists, health-food shops, your doctor and specialist mail order companies. Supplements from the chemist are very strictly controlled as to their content but chemist's shops tend not to include such a wide range of vitamins and minerals in their multivitamin preparations as health-food shops, and they frequently contain tartrazine and other additives which may upset people who are prone to allergies.
Some companies are introducing a range of vitamins and minerals which are described as being in a food state. These are grown in a yeast culture after which the yeast is killed and spray dried, and the resulting mixture made into tablets. It is said that these food-state vitamins and minerals are absorbed more efficiently in the body as they are bound in a more organic form.
Whilst there are intellectual arguments against this view the figures for Magnesium do bear out this contention; it deserves wider exploration, especially in view of possible limiting of dosage by the EC.
Rules for prescribing supplements
Deficiencies When you read through 'Ailments & Conditions', you may find under certain complaints that there may be a need for certain nutrients, such as Vitamin C or Zinc. This means either that the ailment is thought to be due to a deficiency of these nutrients or that it responds to increasing their intake in the diet, although you are not necessarily deficient in them.
If you have this complaint, please find a list of nutrients and harmful substances in the column to the right. This will tell you which foods contain the recommended nutrient, and you should increase your intake of those foods for one month. If this does not help, then take a supplement, in the amount equal to, or less than, that which is advised as a maximum for another month. If there is still no improvement, see your medical doctor, a nutritionally trained physician or a dietician. If you do feel better then you may continue taking the supplement, but stop for 2 days a week. We have deliberately erred on the cautious side when advising dosages of nutrients. However, except with fat-soluble vitamins and certain minerals like Selenium, it is rare to find side effects occurring even if you are taking up to 100 times more than the RDA. Any supplement not mentioned below may also be taken, but stop for 2 days a week after one month, and watch the health press for possible hazards.
In EC countries there is considerable debate at present about the dosage of vitamins and mineral supplements that should be available over the counter. This will probably result in some of the higher potency vitamins and minerals no longer being available. Common sense would state, because of the difficulties in fixing RDAs or DRVs (see below), that apart from some water-soluble vitamins, such as Vitamin C, supplements should not contain more than 10 times the DRV or RDA.
DRVs and food labelling
You may have seen recommended daily allowance (RDA) requirements for various nutrients. These are based on whether a nutrient is essential for the body's health, and the amount required to prevent deficiency and disease. RDAs have varied considerably from country to country, and although not ideal, they seem to work reasonably well to prevent nutritional disease.
The Government Committee of Medical Aspects of Food Policy (COMA) has recently published new dietary reference values for foods, and has introduced the following new terminology.
EAR: the Estimated Average Requirement of a group of people for energy, protein, vitamins and minerals. About half of us usually need more EAR, and about half need less than the LRNI (or the Lower Reference Nutrient Intake) for protein, vitamin and minerals; this is an amount of the nutrient that is enough for only the few people in a group who have low needs.
RNI: a Reference Nutrient Intake for protein, vitamins and minerals. It is the amount of the nutrient that is enough, or more than enough, for about 97 per cent of people in a group. If the average intake of a group is at RNI, then the risk of deficiency in the group is very small.
Safe Intake: a term used to indicate intake, or range of intake, of a nutrient for which there is not enough information to estimate the RNI, EAR or LRNI. It is an amount that is enough for almost everyone but not so large as to cause undesirable effects.
DRV (Dietary Reference Value): a term used to cover LRNI, EAR, RNI and Safe Intake.
The report containing this information is complex, and mainly for professional nutritionists. Nevertheless, it may lead to further recommendations, most of which we have tried to incorporate in this book by giving the new DRVs.
Recently 4 nutritional supplements have had health warnings issued against them, or have been banned in the UK.
Tryptophan was banned from sale in September 1990 by the Department of Health because it was found to be causing a condition known as Eosinophilia Myalgia Syndrome (EMS). This consisted of a rise in certain white cells, severe muscle pains and pains in the joints, fever, swelling and rash. It is still not known whether this is due to tryptophan itself or to some contaminant.
Germanium was marketed as a product to boost the immune system, but in October 1989 all doctors were warned that it could cause diseases of the kidney which could lead to renal failure, and it was then banned.
Niacin has been used for some time to lower cholesterol levels, but it was found that moderately high doses may alter liver function tests; high doses can cause actual liver damage, and can also aggravate diabetes and depression.
Vitamin A see Vitamin A for effects on pregnant women.