Vitamin D supplements: Yes or no?

Thu, 10/08/2020 - 8:30am

    Even before the arrival of COVID-19, millions of people were turning to vitamin D supplements, some to compensate for the diminishing power of the sun here in the northern hemisphere October to March; some as recommended by their doctor for a D deficiency; and others are now taking supplements to try to protect against COVID-19.

    Vitamin D keeps bones healthy by increasing the absorption of calcium in the intestines. Without vitamin D, your body would only be able to absorb about 10% to 15% of the calcium from your diet. - ( Vitamin D helps support our immune and respiratory systems; helps fight off bacteria and viruses; cardiovascular issues, and depression. Deficiency of this vitamin is found in those with conditions including, but not limited to, kidney disease, advanced liver damage, Crohn's disease, cystic fibrosis, and Celiac disease, according to the National Institutes of Health Office of Dietary Supplements at

    Dr. Ron Bouffard BS, DC, DABCI, DACBN, a longtime resident and 25-year practicing chiroprator in Boothbay Harbor, is a Board-Certified Chiropractic Internist and Board-Certified Clinical Nutritionist practicing in Chicago at Aligned Modern Health.

    He orders vitamin D deficiency blood tests for all of his new patients. Bouffard retests his patients’ vitamin D levels three months after prescribing higher doses of vitamin D with K2.

    “Basically, most everyone north of the Mason-Dixon Line, unless they are supplementing is vitamin D deficient. They certainly are in Chicago. There are many reasons to order a vitamin D test: obesity (BMI of 30 and up), gall bladder, long-term use of steroids, drug therapies, liver issues related to alcohol, long-term use of birth control or insulin, aspirin or opiates,” Bouffard said. “If you have weakened lungs and are susceptible to pneumonia, the respiratory system is where COVID-19 attacks.”

    “All the research I’ve seen have higher mortality rates from COVID-19 in those who are vitamin D deficient. There are so many reasons a vitamin D test can be ordered. I order a test for all of my new patients. We don’t just want to find out what’s wrong with you, we want to find out why.”

    In late September, the Boston Herald ran an article on the findings of Dr. Michael Holick, professor of medicine, physiology and biophysics at Boston University School of Medicine. With colleagues, he studied the blood samples of over 190,000 people in every U.S. state from Quest Diagnostics. The result: the samples showing deficient levels of vitamin D “… had 54% higher COVID positivity compared to those with adequate levels of vitamin D in the blood.”

    Dr. Holick isn’t the only one conducting research on the subject. David Meltzer, chief of hospital medicine at the University of Chicago Medicine and lead author of its study, also found a link between vitamin deficiency and contracting COVID-19. Said Meltzer, “Vitamin D is important to the function of the immune system and vitamin D supplements have previously been shown to lower the risk of viral respiratory tract infections. Our statistical analysis suggests this may be true for the COVID-19 infection.”

    The UCM study of 489 of its patients with low vitamin D (less than 20 nanograms per milliliter of blood) had been tracked “within a year before being tested for COVID-19.” Patients whose deficiency went untreated were “almost twice as likely to test positive for COVID-19 compared to patients who had sufficient levels of the vitamin.” (

    Supplements come into play particularly during the darker months of the year, October through April, when the sun isn’t at full power. We are going to work in the dark and return in the dark. People need to be in the sun for 30 minutes a day for our bodies to make vitamin D; direct sun exposure “converts a chemical in our skin into an active form of the vitamin.” ( Because of this synthesis, using sunscreen even a 15 SPF “reduces the benefit of sun exposure 99.9%.”

    Older adults are also more likely to be vitamin D deficient due to the way the aging process affects the skin’s ability to absorb the vitamin in sunlight – and that’s during the warmer months as well. People with with dark skin tones will need more than 30 minutes a day because of the higher melanin levels of their skin. (

    Vitamin and mineral supplements are sold in most supermarkets, chain stores, pharmacies, and through companies online, Puritan’s Pride being an example. Regarding the use of supplements, The Institute of Medicine informs (on its website), “In general, treatment with oral vitamin D does not seem to be associated with serious harms.”

    Dr. Anthony S. Fauci, Director of the National Institute of Allergy and Infectious Diseases and head of the Coronavirus Task Force, said he takes vitamin D supplements. During a Sept. 24 Instagram Live broadcast, he said vitamin D deficiency “does have an impact on your susceptibility to infection. I would not mind recommending, and I do it myself, taking vitamin D supplements.”

    There are dosage recommendations for adults based on recommended daily allowances (RDA) for vitamin D. The RDA is an estimate to meet or exceed adult needs based on minimal time in the sun: 600 IU/day for those aged 1 to 70 years, and 800 IU/day if over 70.

    If you are considering taking a vitamin D supplement, keep in mind there are medications this vitamin interacts or interferes with that may prohibit supplements. Some of these medications are listed on the National Institute of Health (NIH) / Office of Dietary Supplement website at These include, but are not limited to, prednisone and other corticosteroid medicines that reduce inflammation; this reduces the body’s ability to handle vitamin D and  leads to lower calcium absorption and of bone over time.

    And bear this in mind before taking vitamin and mineral supplements: Some weight loss drugs, steroids, cholesterol lowering drug brands, among other maintenance medications, may have an interaction with these supplements. A complete list of drug interactions with vitamin D are on the NIH website at

    One way to find out if you are vitamin D deficient is through a blood test ordered by your primary care physician (PCP) if he or she feels it is warranted. The most common blood test is the 25-hydroxyvitamin D (WebMD). Levels of 20 nanograms/milliliter to 50 ng/mL are considered adequate for healthy people. A level less than 12 ng/mL indicates vitamin D deficiency.

    There are at home test kits that are sent out to, for example, or Each finger prick test is mailed to these company labs that check for everything from iron and vitamin deficiencies to thyroids and COVID-19 testing, with no PCP authorization needed. 
    According to; “No national primary care professional organization currently recommends population-wide screening for vitamin D deficiency. The American Academy of Family Physicians concludes that the current evidence is insufficient to assess the balance of benefits and harms of screening for vitamin D deficiency.”
    The Endocrine Society recommends screening for the deficiency in persons at risk only because “there is a lack of evidence showing benefits of screening at a population level.” And the National Osteoporosis Foundation recommends “testing for vitamin D as part of osteoporosis management or falls prevention” on its website.
    Unless your doctor indicates a test for vitamin D deficiency is medically necessary, Medicare insurance may not cover it. To be considered medically necessary, and covered by your health insurance, your physician might need to provide your provider with documentation of suspected symptoms of deficiency or proof of other medical conditions known to cause a deficiency. The amount of coverage depends on individual insurance plans. As a general rule, testing vitamin D levels relative to COVID-19 may or may not qualify as medically necessary.
    For those on Medicare, Part B coverage may limit the number of times this test can be ordered within a specific time frame. If an underlying medical condition is suspected to create a chronic deficiency, regular testing may be approved for coverage. Check your Medicare materials or visit
    Knowing your vitamin D level, and boosting it if it’s low can offer protection against COVID-19 according to Dr. Joseph Mercola on his website “Based on data from 191,779 American patients, people with a vitamin D level of at least 55 ng/mL (138 nmol/L) had a 47% lower SARS-CoV-2 positivity rate compared to those with a level below 20 ng/mL (50 nmol/L).”
    Besides supplements, diet is also a way to get your daily dose of vitamin D, from fortified foods such as milk, including non-dairy; orange juice, cereals, egg yolks, cheese, beef liver; and fatty fish – salmon, tuna and mackerel. The highest levels of D in foods are, according to, in cod liver oil (1,360 IU); three ounces of rainbow trout (645 IU); and three ounces of sockeye salmon (570 (IU). Among milk products, one cup of 2% milk, vitamin D fortified has 120 (IU); 1 cup of soy, almond and oat milk contains 100-144 (IU).