A recent study found that Vitamin D deficiency may be associated with an increased COVID-19 risk.
Wearing a mask. Staying 6 feet apart. Limiting gatherings. Online ordering. Curbside pickup. Zoom meetings. Working from home. These are all things we’ve become accustomed to in our “new normal” to try to stay safe and healthy during a pandemic. But a recent study completed by the University of Chicago School of Medicine suggests another key player we can add to our protective measures.
Vitamin D has long been understood to be important for bone health and development, ever since mothers first began giving their children cod liver oil to prevent childhood rickets. But the “sunshine vitamin” has more to offer, and is essential to a balanced, healthy immune system.
The study completed by UCM was a retrospective one that looked back over patients who had their vitamin D levels measured within one year before being tested for COVID-19 from March 3 to April 10, 2020. Of the 4,314 tested in that time period, 489 patients had the data needed to be part of the study. One hundred seventy-two, 35%, measured deficient in their vitamin D levels.
Overall, the study found that patients with a deficient vitamin D level had a nearly twice the risk of testing positive for COVID-19 than those that had sufficient vitamin D levels in previous blood tests.
BioSpace spoke to John P. Cooke, MD, Ph.D., Science Advisory Board Member with Humann . Cooke and his team at Houston Methodist Hospital have been researching the innerworkings of COVID-19 within the body.
Cooke explained that there are multiple previous studies suggesting that vitamin D can reduce the incidence of upper viral infections. The mechanisms are not completely understood, but it is thought that vitamin D interferes with viral replication. It also is crucial for activating the killer T-cells, the body’s specialized immune cells that seek out pathogens for destruction.
There are currently 36 studies listed on the NIH database worldwide looking into the relationship between COVID-19 infection and vitamin D.
“There’s now worldwide interest in how vitamin D deficiency might be linked to COVID-19. Whether or not treatment with vitamin D could prevent COVID-19 hospitalization, or once you’re hospitalized if vitamin D supplementation might be useful to increase your chance of survival,” Cooke said.
A small study completed in Spain treated 50 of 76 hospitalized COVID-19 patients with calcifediol, an activated form of vitamin D. Of those 50 patients, only one needed to be admitted to the ICU. All were then discharged without complications. Of the 16 who did not receive calcifediol, 13 were admitted to the ICU and two died. It’s important to note that while these results seem to point to the fact that calcifediol seems to reduce the severity of COVID-19, larger trial populations are needed to firmly establish efficacy.
There is currently no firm guideline at this time from the CDC recommending individuals supplement with vitamin D to prevent severe COVID-19 illness, but Cooke recommends that anyone interested should go ahead and try it.
“It may be as much as half of our population is vitamin D deficient,” Cooke said.
We are an “indoor society” with 90% of our population spending close to 22 hours inside every day. In a YouGov survey in 2018, one in six admitted they practically never go outside, spending up to 24 hours a day indoors. With these modern lifestyles, it’s no wonder that over 80% of COVID-19 patients were found have a vitamin D deficiency.
It’s not only lack of time spent in the great outdoors that is puts us at risk for deficiency. A common risk factor is simply having dark skin, as the higher levels of pigmentation lowers the skin’s ability to make vitamin D in response to sunlight exposure. APM research lab reports that Black Americans experience the highest COVID-19 mortality rates nationwide, with Indigenous and Latino Americans in second and third. Cooper Institute estimates up to 76% of Black Americans are vitamin D deficient.
Other risk factors for vitamin D deficiency include:
- Age – the skin’s ability to make vitamin D lessens with age
- Mobility – homebound individuals or those in nursing homes
- Increased skin cancer awareness – sunscreen and protective clothing block the sun’s UV-B rays
- Location – living in northern latitudes with less sunshine in winter months
- Diet – vegan and dairy-free diets are at higher risk for deficiency
- Medical Conditions – Cystic Fibrosis, Crohn’s, Celiac, weight loss surgery, obesity, kidney and liver disease
- Medications – laxatives, steroids, cholesterol-lowering drugs, seizure-control drugs, TB drug rifampin and weight-loss drug orlistat
If you suspect a vitamin D deficiency, a simple blood test from your doctor can help you understand your risk. Signs and symptoms of a vitamin D deficiency are fatigue, bone pain, muscle weakness, muscle aches or cramps and mood changes like depression.
In the U.S., many of our foods are fortified with vitamin D to prevent deficiency. Dairy products often have it added. Fatty fish like salmon offer an infusion of the immune-boosting vitamin. Egg yolk and fortified cereal also contain some amounts.
If looking to add a vitamin D supplement to your diet, Cooke recommended taking 1-2 a day of the 1,000 IU supplement found at your local pharmacy or vitamin provider. He also recommends taking a Zinc supplement as it may inhibit the attachment of viruses to your epithelial cells, which is his specialty. If unsure about dosage, as it can vary based on health conditions and age, talk to your doctor about your individual needs.
