With winter season just around the corner, many people have started to prepare themselves for days of cold and gloomy weather. As our hours of sunlight begin to dwindle, many Americans grow concerned with receiving less sunshine and in turn, less vitamin D. Over the last several years, there has been several research articles released describing how “deficient” the American (and worldwide) population is in this essential vitamin. Other articles explained the potential health benefits vitamin D offers such as protection against cancer, fractures, type II diabetes, influenza, autoimmune diseases, cancer, heart disease and depression.
Benefits of Vitamin D
It comes as no surprise to see many adults (especially the elderly population) supplementing themselves to reap the benefits of Vitamin D, especially during the winter months. Simultaneously, many Americans hope to prevent any negative consequences of vitamin D deficiency such as poor bone health. Collectively these factors have, not surprisingly, instilled a worldwide vitamin D deficiency pandemic. However, several researchers are recently beginning to question if the population is truly as deficient as it is portrayed.
Vitamin D Deficiency – Is There Really A Pandemic
In the recent study, Vitamin D Deficiency – Is There Really A Pandemic researchers explain that the worldwide assumption that large proportions of Americans are deficient in vitamin D is based on misinterpretation and misapplication of the Institute of Medicine (IOM) reference values.1 Consequently, these misunderstandings can affect patient care. In addition, there have been an increase in lab testing for vitamin D deficiency and this has drawn up healthcare related costs. This pandemic has caused many Americans to consume vitamin D supplements beyond what is actually recommended or needed.
In 2011, the IOM defined the term “deficient”, when applied to vitamin D, as patient’s having serum levels below 20ng/ml or when supplementation with 600 to 800 IU per day fails to achieve this level.1 However, these standards are drawn from averages of a population and thus, may not necessarily be accurate or patient specific. The authors of Vitamin D Deficiency – Is There Really A Pandemic, explain how the IOM develops nutrient Dietary Reference Intakes (DRI).1 This is a broad term for reference values that healthcare professionals can use to assess nutrient intakes of patients. Recommended Dietary Allowance (RDA) is the average daily level of intake sufficient to meet the nutrient requirements of nearly all (97-98%) of healthy people.1
The IOM first begins by gathering values from a large population that will include an EAR (Estimated Average Requirement). This is the median of the distribution of human requirements. The EAR reflects the most likely requirement for the population. However, the RDA, which is commonly used in practice, reflects the estimated requirement for people at the highest end of the distribution. In this sense, practically everyone in the population (approximately 97.5%) will present falsely with a requirement below the RDA.1 Therefore, almost 98% of the country can be seen as deficient when truly, they aren’t.
Recommended Dietary Intakes (RDI)
Currently the recommended dietary allowance (RDA) for those under the age of 70 is 600 International Units (IU) and over 70 is 800 International Units (IU).1 The common misconception is that the RDA acts as a “cut off” point and that nearly the entire must have a serum vitamin D level of 2ng/ml to achieve good bone health.1 The authors explain, that “many studies establish ‘inadequacy’ using the RDA, though it is actually at the upper end of the spectrum of human need”. Clearly this approach misclassifies many as deficient when their nutrient values are actually met. In fact, data gathered from the National Health and Nutrition Examination Survey (NHANES) for 2007 to 2010, reveals that 13% of Americans younger than 70 years old are “at risk” for vitamin D deficiency. In addition, only less than 6% are deficient in Vitamin D (defined as levels < 12. 5ng/ml).1 The authors conclude that “Vitamin D is a nutrient of concern, but these levels of deficiency do not constitute a pandemic”.
The study recommends that patients become aware of and consider risk factors for vitamin D deficiency before they visit their doctors or even think about supplementing themselves. Risk factors for vitamin D that patients should be aware of are osteoporosis, osteomalacia, malabsorption conditions (such as Crohn’s Disease), use of certain medications that affect bone health (some anticonvulsants) and frequent hospitalizations.2 For healthy patients routine screening is not recommended. The authors conclude that “using RDA intake should only be used as a guidepost for healthy individuals”.
Using misinterpreted RDA values as cut-offs and to guide therapy can overestimate the prevalence of vitamin D insufficiency and the needed intake. Unfortunately, this can cause some physicians to recommended increased intake of vitamin D to their patients. Those already on the higher end of the vitamin D spectrum could experience negative effects of too much vitamin D in their bodies. Excessive vitamin D can cause abnormal calcium in the blood leading to nausea, constipation, confusion, abnormal heart rhythm, and even kidney stones.3
Many adults do not account for vitamin D obtained through nutrition and the sun when considering vitamin D supplementation. As with many health conditions, patients fail to get proper blood tests to determine if their vitamin D is actually low and rather decide to supplement with the ease of over-the-counter vitamin D supplements as opposed to discussing their concerns with a health care provider first.
Patients should also keep in mind that they can obtain their vitamin D through a their diet as opposed to over-the-counter supplements. Foods that are rich in vitamin D are fatty fish such as tuna, salmon and mackerel. Other foods that are fortified with vitamin D include orange juice, soymilk, dairy products, cheese, beef liver, egg yolk and some cereals.4 Vitamin D obtained through diet can provide the same amount of vitamin D compared to supplements. For example, six ounces of cooked salmon has more than 600 international units (IU).4
If Recommended Dietary Intakes (RDI) of vitamin D are based off of a misinterpreted estimate, we should be careful not to over-treat vitamin D deficiency. Patients and healthcare professionals should take risk factors into account before deciding to test or not. Many people over-treat their deficiency to get to normal blood levels but they should speak to their physicians whether they should take daily supplements or rather obtain this vitamin through diet and other means.
Hopefully, the eye-opening conclusions drawn from the study, Vitamin D Deficiency – Is There Really A Pandemic can allow patients and healthcare providers to approach this deficiency in a different manner. There is promising research and data expected to be released in the upcoming years regarding vitamin D deficiency and supplementation yet it remains unclear how or even if this will effect physician decision making and patient care. Still, within time, we could expect to see vitamin D deficiency slowly change from a popular health trend into a more personalized health decision.
Written By: Neema Yazdanpanah PharmD
American Integrative Pharmacy
- Manson AE, Brannon PM, Rosen CJ, et al. Vitamin D Deficiency – Is There Really A Pandemic? N Engl J Med 2016; 375: 1817-1820 Nov 10 2016 DOI: 10.1056/NEJMp1608005
- Melamed ML, Kumar J. Low Levels of 25-Hydroxyvitamin D in the Pediatric Populations : Prevalence and Clinical Outcomes. Pediatr Health 2010; 4(1):89-97 http://www.medscape.com/viewarticle/716434_4
- Zeratsky, K. What is vitamin D toxicity and should I worry about it since I take supplements? Mayo Clinic: Nutrition and Healthy Eating 2016 Feb 5 2016 http://www.mayoclinic.org/healthy-lifestyle/nutrition-and-healthy-eating/expert-answers/vitamin-d-toxicity/faq-20058108
- Derrer DT. Top Foods for Calcium and Vitamin D. Web MD Food and Recipes 2016. http://www.webmd.com/food-recipes/guide/calcium-vitamin-d-foods
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