If you’ve ever picked up an item at the grocery store and looked at the label, you’ve probably had some contact with RDA (Recommended Dietary Allowance/Recommended Daily Allowance) and not even known it. RDA was established by the Food and Nutrition Board of the National Academy of Sciences. They are reference values that estimate the minimum daily average dietary nutrient intake level that meets the nutrient requirements of 97-98% of healthy people at various age groups and life stages in the United States, and is one of the three types of dietary reference intakes (DRIs) outlines by the Institute of Medicine. The RDA's are widely used on food labels and other forms of food brochures to give consumers a basis by which to make educated food buying decisions. The question is, how accurate are these numbers?
By definition these figures are intended to meet daily intake minimum requirements and adequacy for human nutrition, not necessarily optimal levels of vitamins and minerals . Even though the RDA's are updated periodically, many dieticians, physicians and researchers argue that they are too low and are not keeping pace with recent advances in nutritional research. While RDA’s take into account age and gender, the way they categorize individuals is often too broad and doesn’t take into account varying lifestyles and outlying medical conditions such as body weight, chronic disease, and other factors that affect nutrition and health. For example, “males 19-30” vary widely but are categorized together. So you could have a 22 year old extremely fit and active soldier in the same category as his overweight, inactive brother who has type 2 diabetes. It’s clear that these two would have extremely different nutritional requirements, especially when it comes to essential nutrients like carbohydrates and macronutrients. Different diet restrictions should also be taken into consideration, as food supplies or even personal choice does not always come with nutrition education that identified the need to up intake of specific nutrients that are lost in dietary changes. Environment also plays a significant role in nutrient needs for a person in addition to whether or not they're in good health. For instance, the most obvious case is Vitamin D. In the winter, when you’re not getting as much through sun exposure, you can make up for this with diet. But the RDA fails to account for this at all, giving just one number that you’re presumably supposed to use year-round to target for adequate intake.
There is ample evidence in the literature and in practice that higher levels of vitamins and minerals play a crucial role in boosting the immune system, enhance cellular health and support brain health and other organs. Recent advances in genetic and microbiome research clearly demonstrate that higher levels of vitamins and minerals are warranted and have positive health impact. The marketplace for vitamins where much higher levels of the RDA's are offered to the public is another evidence that consumers are aware of and asking for higher levels for improved health. Admittingly, some of the offered products have gone too far in providing dosages that are too high and not scientifically substantiated, so consumers need to be aware that more is not necessarily better and can actually have adverse events. Nevertheless, tolerable upper intake levels are being hyper-focused on when it's the estimated average intake requirements that really need a second look to be more in line with modern eating habits.
In conclusion, individuals can benefit from higher levels of vitamins and minerals than the ones recommended by the RDAs but good judgment is necessary and it’s important to rely on the latest substantiated science. If one is going the vitamin supplementation route, it’s important to seek out credible companies that rely on science and operate with high ethical standards. It is up to consumers to educate themselves in the right selection of products and for regulators to properly regulate the marketplace. Bottomline, the numbers in the RDA report are designed to prevent obvious deficiency, not to achieve optimal health.