Ethnic minorities disproportionately affected
It is also well recognized that COVID-19 disproportionately affects black and Asian minority ethnic individuals.
But on the issue of vitamin D in this context, one recent peer-reviewed study using UK Biobank data found no evidence to support a potential role for vitamin D concentration to explain susceptibility to COVID-19 infection either overall or in explaining differences between ethnic groups.
“Vitamin D is unlikely to be the underlying mechanism for the higher risk observed in black and minority ethnic individuals, and vitamin D supplements are unlikely to provide an effective intervention,” Claire Hastie, PhD, of the University of Glasgow and colleagues concluded.
But this hasn’t stopped two endocrinologists from appealing to members of the British Association of Physicians of Indian Origin (BAPIO) to get their vitamin D levels tested.
The black and Asian minority ethnic population, “especially frontline staff, should get their Vitamin D3 levels checked and get appropriate replacement as required,” said Parag Singhal, MD, of Weston General Hospital, Weston-Super-Mare, England, and David C. Anderson, a retired endocrinologist, said in a letter to BAPIO members.
Indeed, they suggested a booster dose of 100,000 IU as a one-off for black and Asian minority ethnic health care staff that should raise vitamin D levels for 2-3 months. They referred to a systematic review that concludes that “single vitamin D3 doses ≥300,000 IU are most effective at improving vitamin D status ... for up to 3 months”.
Commenting on the idea, Dr. Rosen remarked that, in general, the high-dose 50,000-500,000 IU given as a one-off does not confer any greater benefit than a single dose of 1,000 IU per day, except that the blood levels go up quicker and higher.
“Really there is no evidence that getting to super-high levels of vitamin D confer a greater benefit than normal levels,” he said. “So if health care workers suspect vitamin D deficiency, daily doses of 1,000 IU seem reasonable; even if they miss doses, the blood levels are relatively stable.”
On the specific question of vitamin D needs in ethnic minorities, Dr. Rosen said while such individuals do have lower serum levels of vitamin D, the issue is whether there are meaningful clinical implications related to this.
“The real question is whether [ethnic minority individuals] have physiologically adapted for this in other ways because these low levels have been so for thousands of years. In fact, African Americans have lower vitamin D levels but they absolutely have better bones than [whites],” he pointed out.
Testing and governmental recommendations during COVID-19
The U.S. National Institutes of Health in general advises 400 IU to 800 IU per day intake of vitamin D, depending on age, with those over 70 years requiring the highest daily dose. This will result in blood levels that are sufficient to maintain bone health and normal calcium metabolism in healthy people. There are no additional recommendations specific to vitamin D intake during the COVID-19 pandemic, however.
And Dr. Rosen pointed out that there is no evidence for mass screening of vitamin D levels among the U.S. population.
“U.S. public health guidance was pre-COVID, and I think high-risk individuals might want to think about their levels; for example, someone with inflammatory bowel disease or liver or pancreatic disease. These people are at higher risk anyway, and it could be because their vitamin D is low,” he said.
“Skip the test and ensure you are getting adequate levels of vitamin D whether via diet or supplement [400-800 IU per day],” he suggested. “It won’t harm.”
The U.K.’s Public Health England (PHE) clarified its advice on vitamin D supplementation during COVID-19. Alison Tedstone, PhD, chief nutritionist at PHE, said: “Many people are spending more time indoors and may not get all the vitamin D they need from sunlight. To protect their bone and muscle health, they should consider taking a daily supplement containing 10 micrograms [400 IU] of vitamin D.”
However, “there is no sufficient evidence to support recommending Vitamin D for reducing the risk of COVID-19,” she stressed.
Dr. Bajaj is on the advisory board of Medscape Diabetes & Endocrinology. He has ties with Amgen, AstraZeneca Boehringer Ingelheim, Janssen, Merck, Novo Nordisk, Sanofi, Eli Lilly,Valeant, Canadian Collaborative Research Network, CMS Knowledge Translation, Diabetes Canada Scientific Group, LMC Healthcare,mdBriefCase,Medscape, andMeducom. Dr. Kenny, Dr. Rosen, and Dr. Singhal have disclosed no relevant financial relationships.
A version of this article first appeared on Medscape.com.