Answers to Your Questions About Vitamin D
Vitamin D – actually a hormone – is well known for its role in maintaining calcium and phosphorus, both of which are responsible for skeletal health. However, COVID-19 has put Vitamin D supplementation in the minds of many for its lesser-known role as an Immunomodulator and of particular interest for its role in reducing pulmonary inflammation.
While controversial in the past, most evidence to date concludes that Vitamin D does play a role in the prevention of acute respiratory infections and overall immune health. Depending upon what study you are reading, this can be around 10-12% effective in reducing the amount of acute respiratory infections. However, it is essential to note that it really only helps if you are deficient. Those that are deficient and receive supplementation show the most significant benefit. Vitamin D has been discovered to trigger an immune response to some viruses and bacteria and to inhibit pulmonary inflammation, which besides acute respiratory infections, is being studied for asthma, cystic fibrosis, and COPD, among others.
Of course, we all know now that COVID-19 causes respiratory infection, but so can the common cold, pneumonia, flu, and bronchitis, and while evidence suggests these can be worsened by vitamin D deficiency, other risk factors include air pollution and exposure to smoke.
Recent clinical and epidemiological studies suggest that vitamin D deficiency may play a role in several additional conditions, including Seasonal Affective Disorder, some cancers, heart disease, hypertension, multiple sclerosis, and type 1 diabetes.
Who is at risk for Vitamin D deficiency?
Vitamin D is not a vitamin at all. It is a hormone synthesized in the body when sunlight is exposed to bare skin. If you routinely stay indoors or protect yourself from sunlight with sunscreen or live in latitudes without sufficient sun exposure, you will typically have less vitamin D.
Today, many facial moisturizers include sunscreen, and it has been demonstrated that using a moisturizer or sunscreen as low as 15 SPF can reduce your vitamin D production by 99.9%. (1)
Furthermore, if you live in Chicago or another area with atmospheric pollution, this can block the sun’s ultraviolet rays, and also appears to be a factor in increasing the risk of vitamin D deficiency. (1)
Of course, other factors can include the season (winter days are shorter and provide less opportunity for outdoor sunlight exposure), and even in summer months, you may not spend so much time outdoors. Strict vegetarians, age, alcoholics, absorption capacity, people with liver or kidney disease, or darker skin pigmentation are also shown to be at a higher risk for Vitamin D deficiency.
Vitamin D deficiency is common in patients with digestive disorders Such as Celiac disease, IBS, or Crohn’s disease because of the ability to absorb nutrients.
In one study, One in seven Americans were found to have a vitamin D deficiency (4,5). Surprisingly, the same study also discovered that 37% of the patients eating the recommended amounts of Vitamin D in their diet were still found to be deficient.
How Much Vitamin D Should You Take?
Vitamin D supplementation is only beneficial if you are deficient. Although Vitamin D’s benefits are many and have been widely studied, at high doses, vitamin D can have a toxic hypercalcemic effect if taken blindly. Many Americans are deficient in vitamin D, and it has been shown that daily multivitamins provide inadequate supplementation. Current research demonstrates that circulating vitamin D levels in your blood should be in the range of 50 to 80 ng/mL and individuals in this range show reduced mortality and a lower risk of common diseases.
The best vitamin D source is 10 minutes a day of bare skin exposure to sunlight without sunscreen.
Be sure to include vitamin D into your diet by eating a diet that includes fatty fish such as mackerel or salmon. Trace amounts of vitamin D are also found in egg yolks.
In our office, we supplement deficient patients with Vitamin D3, also known as “cholecalciferol”. “Ergocalciferol” or “D2” should be avoided as this is the synthetic form.
You do not know if you are deficient or how deficient you may be unless you know your vitamin D status.
Optimal levels in healthy individuals are in the 50-90 ng/mL range.
Vitamin D status is so important to your health that we include it in our standard panel of testing for our patients.
Please speak to one of our expert team members today to determine your vitamin D status. 773.878.7330
This article is for information purposes only: No supplement can prevent you from acquiring COVID-19.
Holick MF and Jenkins M, The UV Advantage: The Medical Breakthrough That Shows How to Harness the Power of the Sun for Your Health, New York, NY: ibooks, 2003.
Endres DB and Rude RK, “Mineral and Bone Metabolism,” Tietz Textbook of Clinical Chemistry, 3rd ed, Burtis CA and Ashwood ER, eds, Philadelphia, PA: WB Saunders, 1999, 1395-457.
Holick MF, “Vitamin D: A Millenium Perspective,” J Cell Biochem, 2003, 88(2):296-307.
Chapuy MC, Preziosi P, Maamer M, et al. Prevalence of vitamin D insufficiency in an adult normal population. Osteoporos Int 1997;7:439–43.
Thomas MK, Lloyd-Jones DM, Thadhani RI, et al. Hypovitaminosis D in medical inpatients. N Engl J Med 1998;338:777–83.
Harris SS, Dawson-Hughes B, Perrone GA. Plasma 25-hydroxyvitamin D responses of younger and older men to three weeks of supplementation with 1800 IU/day of vitamin D. J Am Coll Nutr 1999;18:470–4.
Hollis BW, “Circulating 25-Hydroxyvitamin D Levels Indicative of Vitamin D Sufficiency; Implications for Establishing a New Effective Dietary Intake Recommendation for Vitamin D,” J Nutr, 2005, 135(2):317-22.