When the pandemic was at its peak, many people were searching for the golden ticket to reduce their risk of contracting COVID-19. Vitamin D became the new “hot” supplement for its potential to ward off infections. Can vitamin D really protect you from getting COVID-19?
What is vitamin D?
Vitamin D is a fat soluble vitamin that we mainly get from the sun, which is why it is known as the sunshine vitamin (1). What is super interesting about vitamin D is that it functions like a hormone. Vitamin D helps regulate many processes in our bodies. Some of the important roles of vitamin D include:
- Supports bone structure
- Regulates calcium and phosphate levels in our blood
- Contributes to nervous system development and cell growth
- Helps suppress inflammation by reducing pro-inflammatory chemical production and inflammatory T-cells
- Regulates tight junctions in our intestinal barrier to prevent leaky gut
Can vitamin D protect against COVID-19?
Several observational studies have assessed vitamin D levels and its role in both positive COVID-19 cases and severity of disease. Most of the studies have linked vitamin D deficiency to an increased risk of contracting COVID-19, but have not shown a relationship between the severity of the disease and vitamin D status. One study found that individuals with a vitamin D deficiency had a 1.77 times greater risk of testing positive for COVID-19 (3). Another study looked at vitamin D levels in both COVID patients and healthy participants and found a vitamin D deficiency in 82.2% of COVID-19 patients and 47% in non-COVID-19 individuals (4).
While this all sounds like vitamin D is the solution to preventing COVID-19, take these studies with a grain of salt. Most of this research was based on observations, so it only indicates associations and not causations. Many of the risk factors for COVID-19 are the same for vitamin D deficiency, including:
- Older age – as we age, our vitamin D levels tend to fall
- Obesity – individuals who carry excess weight sequester vitamin D in adipose tissue, lowering vitamin D levels in circulation
- Minorities – people with darker skin are less efficient at absorbing vitamin D from the sun.
How do we increase our vitamin D levels?
Get tested: The first step is to make sure you are actually vitamin D deficient. Vitamin D is checked by a simple blood test. Ask your health care provider to check your vitamin D levels at least once a year.
Get outside: Sunlight is your best source of vitamin D. Some experts recommend 5-30 minutes of non-sunscreen exposure to sunlight twice per week on your face, arms, legs and back. However, if you are concerned about skin cancer, please check with your health care professional or dermatologist to find the right amount of sun exposure for you (5).
Eat vitamin D-rich foods: The recommended daily amount of vitamin D for 19-70 year olds is 600 IU, and 800 IU for over 70 years of age. Foods rich in vitamin D include cod liver oil, rainbow trout, salmon and fortified milk and cereals.
Last resort – supplements: If you don’t get outside enough or live in an area where sunlight is not strong enough and you struggle to get vitamin D-rich foods into your diet, supplementation may be warranted. Please consult your health care professional prior to taking vitamin D supplements. Vitamin D is fat soluble, meaning that it stores readily in your body, and taking too much can increase your risk of toxicity.
While a sufficient amount of vitamin D can keep your body healthy and fight off some infections, it is probably not the quick fix to prevent COVID-19. However, vitamin D plays many important roles in your body, so having a solid vitamin D level can benefit your overall health.
Annie Rubin, MS, RDN, May 11, 2021