In other words, if the FDA decides, for instance, that there is no benefit to be had in consuming supplements containing vitamin C at levels above the U.S. recommended daily amount (RDA) - currently set at a mere 7 5 mg/day for females and 90 mg/day for males - then the fact that vitamin C, in its ascorbic acid form, can cause diarrhoea above tolerance levels could potentially trigger an "unreasonable risk of illness or injury" classification and subsequent restrictions upon its sale.

As such, given that many of the health benefits attributed to nutritional supplements effectively put them in the area of what is currently defined as drug use (i.e. they prevent, reduce the risk of, or even treat diseases), the implication is that the FDA could, in future, simply decide that such benefits do not apply to products regulated as supplements, and assign the benefit portion of any risk-benefit analysis for nutrients to zero. By establishing this precedent, and ruling in favor of this methodology, the 10 th U.S. Circuit Court of Appeals would therefore seem to have tipped the U.S. regulatory scales significantly in the FDA’s favor.

Clearly, therefore, the continued ignoring by national regulatory agencies of the health benefits of consuming above-RDA levels of supplemental nutrients is now a serious threat to their future availability.

The need to consider all of the evidence

In some areas of the world, such as the United States and the United Kingdom, supplemental nutrients have been in use for over half a century now. As a result, some doctors and practitioners have built up extensive databases containing carefully documented case histories of patients who have used high doses of vitamin and mineral supplements, safely and effectively, for many years. Similarly, research scientists have conducted numerous small-scale clinical trials that have produced impressive results providing clear evidence of the safety of high dose supplements in human beings.

Nevertheless, a serious flaw in the current regulatory approach to nutrient risk assessment is that some of the most valuable potential sources of positive scientific evidence regarding the use and safety of supplements, such as the types of observational and clinical data described above, are generally ignored. Instead, the sole source of evidence that is considered are peer-reviewed scientific studies of particular nutrient forms, which are often non-comparable owing to differing experimental designs, nutrient forms delivered, dosages given, and so on.

The net result of this is that the evidence-base for nutrient risk assessment tends to be skewed towards consideration of negative outcome studies that used a single vitamin or mineral - frequently in a synthetic rather than a naturally-occurring form – without full and proper consideration of the participants’ overall state of health or individual nutritional requirements. Moreover such studies are often non-comparable owing to differences in their follow-up periods; the fact that many have been conducted on diseased rather than healthy populations; and that many were started well after disease states had already been initiated. As a result, a process that may appear rational, objective and scientific to the lay person or even the regulator, is, we discover, actually flawed and deeply unscientific.

Upper safe levels versus maximum permitted levels