Explaining the Recommended Daily Allowance (RDA)

Health and Wellness Update – Explaining Nutritional Gaps    From Shaklee Health Sciences, July 29, 2014


“Most people misunderstand what the Recommended Daily Allowances (RDA) means. The RDAs are nutritional recommendations from the Food and Nutrition Board appointed by the Institute of Medicine (IOM) of the U.S. National Academy of Sciences. The RDA is the amount of a given nutrient that is the minimum amount needed to avoid being deficient and at risk to develop the deficiency disease (for instance pellagra from niacin deficiency, scurvy from Vitamin C deficiency, rickets or osteomalacia from Vitamin D deficiency and others).

The RDA is not necessarily the optimum amount and is most certainly not a measure of the upper level of a nutrient that you wouldn’t want to exceed.

When RDA levels are consumed, you can be fairly assured that you will avoid the deficiency diseases. For some nutrients, though, the RDA amount may not reflect what the general recommendations for intake might be – as we increasingly understand the needs of our bodies for higher levels of certain nutrients in today’s world. Additionally, many important nutrients don’t have an established RDA (such as lycopene, EPA/DHA, and many other nutrients).

The RDA does not take into consideration an individual’s personal situation (maybe they work in a toxic environment), or lifestyle factors (maybe they eat fast food at every meal), or that they are frequently dieting, or considering getting pregnant. Your genetics may also put you at risk for needing higher intake of certain nutrients.

While the RDA are pretty reasonable amounts to aim for, especially for minerals, there are a host of reasons why higher intakes of some nutrients may be a good idea:

  • B-Vitamins are a group of water-soluble vitamins that are used throughout the body primarily as co-factors. Because they are water-soluble, your body needs a constant supply of them. Among their many functions, they are used to optimize brain function – including mood and memory, and they help the body to handle and adapt to stressful situations. i
  • Carotenoids are a group of antioxidants that only some of which have RDA established for them.
    • Alpha and Beta-carotene are both helpful antioxidants by themselves and they also can be converted into vitamin A when the body needs it and, therefore, much safer to consume than vitamin A. These carotenes and vitamin A are good for eyes and skin.ii
    • Lycopene has many uses, but is often recommended to support prostate health. iii
    • Lutein/Zeaxanthin are related carotenoids that are helpful for lifelong eye health.iv
  • Vitamin C is an essential co-factor for the synthesis of collagen, carnitine, and many hormones. It also acts as a potent antioxidant. Higher intakes of vitamin C from either diet or supplements are associated with good heart health. v
  • • Vitamin D is one of most common nutrient deficiency for people who do not supplement. Vitamin D aids in the absorption and utilization of calcium into bones. It is also thought to help maintain the health of the heart and immune system.vi
  • Vitamin E comes in many forms (gamma-tocopherol, beta- tocopherol, and delta-tocopherol). They all act as powerful antioxidants, are important for heart health, eye health, and long-term cognitive health.vii
  • Omega-3 fatty acids (EPA/DHA) are another category of under-consumed nutrients for which an RDA is not established. These fatty acids play many important roles throughout the body and are important for heart health, brain health, and the functioning of cells throughout the body.viii
  • Probiotics are healthy types of gut bacteria; scientists are continually learning more about the role the overall microflora plays in good health. Probiotics help to regulate bowel movements, but are also important for the absorption and synthesis of vital nutrients and appear to play an important role in immune function.ix

The establishment of the RDA was a great milestone in nutritional history. For the first time we had guidelines that helped us understand what minimum amounts of nutrients we need to avoid deficiency diseases. In order to optimize health, though, we may need to choose higher amounts of certain essential nutrients than just the RDA. “http://content.shaklee.com/shaklee/video/player.php?video=WhySupplement

i Calvaresi E, Bryan J. B vitamins, cognition, and aging: a review. J Gerontol B Psychol Sci Soc Sci. 2001 Nov;56(6):P327-39. PMID: 11682586.
ii Seddon JM, Ajani UA, Sperduto RD, et al. Dietary carotenoids, vitamins A, C, and E, and advanced age-related macular degeneration. Eye Disease Case-Control Study Group. JAMA. 1994 Nov 9;272(18):1413-20. Erratum in: JAMA 1995 Feb 22;273(8):622. PMID: 7933422.
iii Giovannucci E. Tomatoes, tomato-based products, lycopene, and cancer: review of the epidemiologic literature. J Natl Cancer Inst. 1999 Feb 17;91(4):317-31. PMID: 10050865.
iv Moeller SM, Parekh N, Tinker L, et al. Associations between intermediate age-related macular degeneration and lutein and zeaxanthin in the Carotenoids in Age-related Eye Disease Study (CAREDS): ancillary study of the Women’s Health Initiative. Arch Ophthalmol. 2006 Aug;124(8):1151-62. PubMed PMID: 16908818.
v Knekt P, Ritz J, Pereira MA, O’Reilly EJ, et al. Antioxidant vitamins and coronary heart disease risk: a pooled analysis of 9 cohorts. Am J Clin Nutr. 2004 Dec;80(6):1508-20. PMID: 15585762.
vi Tamez H, Kalim S, Thadhani RI. Does vitamin D modulate blood pressure? Curr Opin Nephrol Hypertens. 2013 Mar;22(2):204-9.. PMID: 23299053.
vii Masaki KH, Losonczy KG, Izmirlian G, et al. Association of vitamin E and C supplement use with cognitive function and dementia in elderly men. Neurology. 2000 Mar 28;54(6):1265-72. PMID: 10746596.
viii Kromhout D. Omega-3 fatty acids and coronary heart disease. The final verdict? Curr Opin Lipidol. 2012 Dec;23(6):554-9. PMID: 23010698.
ix Cunningham-Rundles S, Ahrné S, Bengmark S, et al. Probiotics and immune response. Am J Gastroenterol. 2000 Jan;95(1 Suppl):S22-5. PMID: 10634225.




About Marsha Ann Brown

I love the spirit of enterprise and use smart health solutions and online marketing strategies to empower leaders and inspire lasting success.
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