Nutritional medicine in need of experience
Whatever happened to evidence-based medicine? Nowhere in dietitian Catherine Collins' review of nutritional supplements (Clinical, April 19) does she mention that concentrations of essential minerals can be accurately assessed, even at levels of parts per billion, at the request of medically qualified practitioners.
She ignores the fact that both pregnancy and contraceptive and menopausal hormones lower
zinc and raise copper levels to
the point where a different reference range for serum zinc has been suggested for hormone-takers1.
Zinc is essential for normal brain development and function and is needed for normal DNA and RNA mechanisms, including repairing damage that may lead to cancer. In zinc deficiency the numbers of immune-regulating lymphocytes are grossly reduced.
Nine out of 10 of my patients are zinc deficient and most are also magnesium deficient when first inveatigated.
Many women become copper deficient, which can be diagnosed using a red cell test of SODase function, due to prolonged use of hormones raising tissue copper concentrations.
Magnesium is the second commonest deficiency. Magnesium can be difficult to supplement if there are absorption problems and selenium supplementation may also be needed2.
Doctors practising monitored essential nutrient repletion usually recommend enough magnesium to restore red cell magnesium levels to normal. The doses obviously have to be below the amount needed to cause diarrhoea.
How many members of the Expert Group on Vitamins and Minerals, who want to restrict available doses, have first-hand experience of practising nutritional medicine with monitored repletion of common multiple deficiencies?
Judging by their conclusions, it seems very few.
Dr Ellen Grant
1. Kumru et al. Comparison of serum copper, zinc, calcium and magnesium levels in
pre-eclamptic and healthy pregnant women. Biol Trace Elem Res. 2003;94:105-12
2. Howard et al. Red cell magnesium and glutathione peroxidase in infertile women – effects of oral supplementation with magnesium and selenium. Magnesium research