Shedding light on Vitamin D: Is there a connection to COVID-19?

April 8, 2020 GMT


Lifestyle CoachSome people have little or no symptoms from COVID-19 and others, young and old, are dying all around the world. We know one protective factor is a strong immune system. What helps create a strong immune system?

While many factors are at play, including age, overall health, good nutrition, exercise, adequate rest and managing stress effectively, there are current theories circulating about what other factors might help fight this deadly virus. Since COVID-19 research is rapidly changing, this discussion is more of an interest in how nutrition and specifically Vitamin D may play a part. Discovered in 1920 as a cure for rickets, Vitamin D is now well known for aiding in absorption of calcium from the gut, maintaining bone health, brain function, a strong immune system and reducing inflammation. Studies also indicate that low levels of Vitamin D are associated with higher risk of respiratory diseases such as chronic obstructive pulmonary disease and asthma and is also linked with decreased lung function, which might make the lungs more vulnerable to infection especially in older adults or those with lung issues.


Should we be concerned? Maybe. According to a 2006 and follow-up American study in 2012, approximately 40 percent of 5,000 random adults in both studies were insufficient in Vitamin D, classified as less than 50 mmol/L in a blood test.

People at risk for Vitamin D deficiency include older adults, people with limited sun exposure, people with dark skin, people with gut issues that make it harder to absorb Vitamin D (such as Crohn’s and celiac disease) and people who are obese or have had gastric bypass surgery.

Sunlight is the best way to get vitamin D, as it turns a chemical in your skin to Vitamin D3, which is then transformed to active Vitamin D in the body.

Many people don’t get outside enough, and sunscreen might block some of the light to prevent absorption. If you do want to get Vitamin D from the sun, guidelines from the Vitamin D Council suggest 15 minutes per day for lighter skinned people and as much as 120 minutes per day for darker skinned people. Current advice is for people to stay in the sun for half as long as it takes their particular skin type to burn before covering up and seeking shade. This should give adequate vitamin D without increasing the risk of skin cancer.

What about food? Most foods don’t contain a significant amount of vitamin D naturally, but it is found in fatty fish, like salmon and tuna, eggs, mushrooms and fortified foods. Fortified foods provide the most Vitamin D in the American diet and is added to cow’s milk, many plant milks, cereals and some brands of orange juice, yogurt, margarine and other food products.


The amount of Vitamin D is required on the nutrition facts panel of food products, so check the label for Vitamin D. The daily reference intake requirement for Vitamin D is in International Units, or IUs, and for 0-12 months is 400 IUs, 600 IUs for ages 1 to 70 and 800 IUs above age 70.

Supplements are another form of Vitamin D and can be found in fish oils or sold alone as a supplement. Vitamin D3 is better utilized in the body and is the preferred form to take. How much do you need to take? Talk to your provider about any supplements you might be taking.

If you are significantly deficient, your provider will recommend 50,000 IU’ taken on a consistent basis until the levels are normal and usually will recommend a maintenance dose of 1,000 to 4,000 IUs daily. Most experts do not recommend taking more than 5,000 IUs per day, and levels need to be checked as Vitamin D can build up over time and become toxic.

While there is no current evidence that Vitamin D deficiency is linked to COVID-19, it is important to consider that optimal levels in the body are one aspect of keeping the immune system strong and protecting the lungs. Easy steps are eating foods fortified in Vitamin D, getting out in the sun safely and talking to your provider about bloodwork and supplementation.

Stay safe out there.

For more information on adopting healthier lifestyle changes, contact Kitty Finklea, a lifestyle coach, registered dietitian and personal trainer at McLeod Health and Fitness Center, at 843-777-3000.