The Health Diva

How much do you need of the various vitamins and minerals?

In 1941, a committee of the National Academy of Sciences suggested for the first time a “Recommended Daily Dietary Allowance” (RDA) of nutrients.  These guidelines were developed in the hope of reducing the incidence of nutritional deficiency diseases such as scurvy (deficiency of vitamin C), pellagra (deficiency of niacin) and beri-beri (deficiency of B-1) in the general population. There’s a big difference between the amount required to prevent deficiency, and the amount of each vitamin and mineral you need for optimum health. A few years ago, scientists at the University of Alabama worked this out for every nutrient and called the amounts Suggested Optimal Nutrient Allowances (SONAs).

SONAs take into account a growing body of evidence that indicates that intakes of certain vitamins and minerals above the RDAs may be necessary to protect against the development of certain chronic diseases. These vitamins may be required in much higher amounts than the RDA to prevent atherosclerosis than needed to prevent deficiency symptoms. The same might be true of many cancers, heart disease, or eye diseases (e.g. macular degeneration or cataracts).

As a nutritionist I find SONAs to be a good indication of what supplement levels to take.

Table 1. Comparing Daily RDA levels with SONAs, for children and adults.