The concluding remarks in the abstract from a research paper published in the American Journal of Clinical Nutrition in 19881 stated that: ‘we conclude that multivitamin and mineral supplementation was without any measurable ergogenic effect and that such supplementation is unnecessary in athletes ingesting a normal diet’. The study involved measuring serum levels of vitamin and minerals as well as the iron status of a number of subjects who were long distance runners. The runners were well trained males aged between 20 and 45 years and were involved in competitive distance running for at least 3 years. The estimated training distance was over 70 km per week. The subjects were asked to cease any multivitamin and mineral supplement for 6 weeks prior to the study commencing and in a double blind fashion were then administered a multivitamin and mineral supplement or a placebo for 3 months.
One of the first indicators that this was a poorly designed study were the low levels of vitamins and minerals in the supplement. A number of essential minerals were also missing from the tablet including chromium, molybdenum and boron. In addition, the levels of some of the vitamins and minerals were below the recommended daily amount, a levels that has been shown to be insufficient for even sedentary individuals in many cases. The tablet provided just 60 mg of vitamin C and just 10 µg of vitamin D. For example, 10 µg vitamin D is 5 times lower than the current intake recommended for the prevention of serious disease. The authors argued that the supplements provided no ergogenic aid to the athletes and was therefore worthless. However, no measurements of performance were measured or recorded and as such this conclusion is invalid and should not have been included.
The claim that that plasma levels of the minerals did not change with the supplement compared to the placebo for the entire duration of the study is also erroneous. The athletes did experience a significant increase in both pyridoxine and riboflavin levels, which argues against their premise that supplementation had no effect. A rise in two vitamin levels in the plasma is positive effect, or at least it is to those who care about details such as accurate science. In addition, it has been shown that measurements of plasma levels of certain vitamins and minerals is dependent on the form of the micronutrient measured, is not a suitable method for accurately assessing some micronutrients and is heavily dependent on the biochemical assay employed. The fact that iron deficiency symptoms were not present in any of the subjects prior to the study would also make one question the relevance of testing a number of iron related parameter.
The authors also suggested that the diet of the athletes was suitable for their needs. However, this was contrary to their own findings whereby the mean energy intake of the athletes was below the recommended energy intake for sedentary individuals. This despite running 70 km per week on average. Clearly their diet was not suitable, and it is very unlikely that intakes of minerals and vitamins would be anywhere near high enough from so few calories without the use of a supplemental form of micronutrients. Such nutritionally poor research should not pass peer review, and it is a wonder that such a pointless and poorly written paper ever made it to publication. There is a large body of evidence that sedentary individuals eating a Western diet have low intake of many vitamins and minerals and physical activity increases this requirement further.
The real purpose of this research becomes clear when the authors refer to the vitamin and mineral supplement as a ‘medication’. This is telling, because it shows that the authors do not really understand nutrition and is an indication that their façade as ‘nutrition researchers’ had temporarily dropped. A quick look at the authors list shows that the contributory authors were in fact doctors, or had medical qualifications. Treating nutrients as pharmaceuticals is poor science because nutrients do not work like drugs (although some can at very high concentrations). It was Dr Joel Wallach that first pointed out that the average age of citizens in the United States was 76 years but that the average age of medical doctors was 56 years. With advice to avoid supplements and eat a Western diet, the reason for this anomaly appears clear. Perhaps the doctors involved knew most readers would not read past the abstract? Must try harder.
RdB
