UNC scientist: Vitamin D deficiency could increase susceptibility to COVID-19
KANNAPOLIS — Getting enough vitamin D could help people avoid contracting COVID-19 and other respiratory infections, according to a review article by a scientist at the UNC Nutrition Research Institute in Kannapolis.
Dr. Martin Kohlmeier, a UNC-Chapel Hill professor and director of its Human Research Core and Nutrigenetics Laboratory, wrote the article, which claims vitamin D deficiency “impedes good immune function” and is common during winter and spring months in high-latitude areas.
“In the case of the current COVID-19 pandemic, vitamin D deficiency may provide the virus with an unguarded opening to spread from deficient to deficient individual when there are just too many of them,” the article states.
Kohlmeier has been studying nutrition for 30 years, and specifically studies precision nutrition, which takes a broad set of information including genetics to make decisions about nutrition for the individual.
Kohlmeier said there is evidence that vitamin D deficiency contributes to seasonal incidence of respiratory infections like the common cold and the flu and that COVID-19 is more infectious than the influenza, often spreading to 75% of the people in a household when brought home.
“This is a very vicious, highly infectious disease,” Kohlmeier said, adding a healthy immune system is capable of stopping a number of infections without having ever encountered them before.
Increased immune function in the summer due to higher vitamin D levels helps ward off respiratory illness, he said.
About 15 minutes outside at the peak of sunlight during the summer can keep people’s vitamin D supply healthy, he said. But not everyone goes outside in the middle of the day. The colder months and genetics can even pose a challenge as well.
Kohlmeier said there is about four-month window in North Carolina in the colder months where it is impossible to create a sufficient amount of vitamin D through exposure to sunlight, and this leads to mass deficiency as stores of the vitamin deplete.
In areas farther north, like New York, the time during the year when the body can not produce enough vitamin D via sunlight is considerably longer.
Kohlmeier said darker skin tones can also make it more difficult to produce the vitamin D people need naturally, and this can disproportionately affect African-Americans. Melanin, the pigment in skin, is like a natural sunblock, he said.
A simple daily vitamin D supplement can keep people from becoming deficient at any time of year, and Kohlmeier said the benefits of having enough vitamin D can be seen within a few days. Doing so also costs just cents per day, but Kohlmeier said it is uncommon for doctors to recommend a vitamin D supplement to patients.
There is some vitamin D in dietary sources like fatty fish, but Kohlmeier said it is difficult to get enough from food.
According to Mayo Clinic, a 600 IU supplement is sufficient for most people, and 800 IU for people older than 70.
“I have been taking one for years,” Kohlmeier said.
Vitamin D deficiency also affects bone health, mood, increased risk of diabetes, multiple sclerosis and other diseases. Vitamin D can help prevent some cancers, improve cognitive health and treat inherited disorders