Why vitamin D keeps taking the spotlight in the pandemic

By now, we all know the symptoms of COVID-19, as well as the measures to take to prevent spread of the disease. As cases rise with the colder months, it’s more important than ever to wash your hands, wear your mask and practice social distancing, which means no large holiday gatherings with people outside your immediate family.

Scientists continue to work nonstop to understand the complexities of the SARS-CoV-2 virus and the illness it causes in the hope of discovering effective treatments for it, as well as additional measures we can take to protect ourselves against it. So far, researchers have not identified any specific supplements that can help defend against COVID-19. But one study indicates that shortage of an important nutrient could be linked with COVID-19 infection…

The COVID-vitamin D connection

A study published in the Endocrine Society’s Journal of Clinical Endocrinology & Metabolism revealed that more than 80% of COVID-19 patients hospitalized in Spain were vitamin D deficiency. This vital hormone produced by the kidneys controls blood calcium concentrations and helps regulate the body’s immune response. Vitamin D also increases the effectiveness of immune cells like T-cells and macrophages and has been connected in studies to protect against infections.

Shortage of vitamin D can cause a loss of bone density, and in severe cases can lead to bone diseases, like rickets in children and osteomalacia in adults. Researchers are studying the possible connection between vitamin D deficiency and medical conditions such as diabetes, high blood pressure, cancer and autoimmune disorders such as multiple sclerosis.

But what’s interesting in terms of COVID-19 is that low vitamin D levels can also raise the risk of respiratory diseases like tuberculosis, asthma and chronic obstructive pulmonary disease, as well as respiratory infections caused by bacteria and viruses. Since COVID-19 can cause severe respiratory distress, it’s possible a shortage of vitamin D could make the situation worse.

The Endocrine Society study found 80 percent of 216 COVID-19 patients at the Hospital Universitario Marqués de Valdecilla in Spain had a shortage of vitamin D, and men had lower vitamin D levels than women. The vitamin D deficient COVID-19 patients also had raised serum levels of inflammatory markers such as ferritin and D-dimer and a greater prevalence of hypertension and cardiovascular diseases.

The researchers cautioned that the observational study doesn’t really allow them to establish whether vitamin D deficiency is a biomarker of exposure or a biomarker of effect on COVID-19. No relationship was found between low vitamin D levels and COVID-19 severity.

But it’s important to note this is not the first time that COVID-19 has been linked to low levels of vitamin D…

At Northwestern University in Illinois, a research team conducted a statistical analysis of data from hospitals and clinics across China, France, Germany, Italy, Iran, South Korea, Spain, Switzerland, the United Kingdom and the United States.

They noticed that patients from countries with high COVID-19 mortality rates, such as Italy, Spain and the United Kingdom, had lower levels of vitamin D, compared to patients in countries that were not as severely affected.

In addition to that, a small clinical trial in which some patients with confirmed cases of COVID-19 were treated with Calcifediol, the main metabolite of vitamin D3, had very positive outcomes. You can read more about specifics on how they put vitamin D to the test here.

Maintaining healthy vitamin D levels

According to the lead researcher of the study in Spain, Dr. José L. Hernández of the University of Cantabria in Santander, “One approach is to identify and treat vitamin D deficiency, especially in high-risk individuals such as the elderly, patients with comorbidities and nursing home residents, who are the main target population for the COVID-19.

“Vitamin D treatment should be recommended in COVID-19 patients with low levels of vitamin D circulating in the blood since this approach might have beneficial effects in both the musculoskeletal and the immune system.”

It can be surprisingly difficult to maintain healthy vitamin D levels. Many of us don’t get enough sun exposure for the body to make its own vitamin D, particularly now with colder weather setting in. And there are a host of conditions that make it difficult to produce enough vitamin D, including chronic kidney and liver diseases, obesity, Crohn’s disease, celiac disease and osteoporosis.

To keep your vitamin D levels where they should be for optimum health, it’s recommended that adults between the ages of 19 and 70 get at least 600 IUs of vitamin D daily. Adults 71 years and older need more, about 800 IUs a day.

You can get vitamin D from foods such as fatty fish, beef liver, cheese, mushrooms and egg yolks, as well as vitamin D-fortified foods like milk, breakfast cereals, orange juice and soy drinks. Many multivitamins have vitamin D, or you can take a vitamin D supplement.

If you think you may be deficient in vitamin D, you can have your doctor test your blood levels of the hormone, or you can do it yourself with an at-home kit. Once you know how low your vitamin D levels are, you can supplement to get them back to healthy levels. Depending on how severe your deficiency is, you could need anywhere from 1,000 to 5,000 IU per day to get your levels up and just to maintain them. These levels are far below the amount to cause vitamin D toxicity, which is 60,000 IU daily for 3 months.


Study finds over 80 percent of COVID-19 patients have vitamin D deficiency — Endocrine Society

Vitamin D Status in Hospitalized Patients with SARS-CoV-2 Infection — The Journal of Clinical Endrocrinology & Metabolism

Vitamin D Deficiency — MedlinePlus

Does Your Vitamin D Level Play a Role in Your Covid-19 Risk? — Easy Health Options

Carolyn Gretton

By Carolyn Gretton

Carolyn Gretton is a freelance writer based in New Haven, CT who specializes in all aspects of health and wellness and is passionate about discovering the latest health breakthroughs and sharing them with others. She has worked with a wide range of companies in the alternative health space and has written for online and print publications like Dow Jones Newswires and the Philadelphia Inquirer.