Industry asserts vitamin D supplementation effective for COVID-19 prevention
12 Sep 2022 --- The Council for Responsible Nutrition (CRN) is responding to studies conducted in the UK and Norway, that unveiled a correlation between vitamin D consumption and the progression of COVID-19.
The two studies published in the British Medical Journal found that the best method of preventing COVID-19 is still vaccination. Moreover, vitamin D and cod liver oil supplements shouldn’t be given to healthy individuals with appropriate vitamin D levels.
“Two new studies from the British Medical Journal on vitamin D and COVID-19 should be read cautiously, despite some overly simplistic early media coverage,” says Luke Huber, VP of scientific and regulatory affairs at CRN.
“Reporting on this research that suggests vitamin D levels are not relevant to COVID-19 outcomes ignores the large body of research on this connection and downplays critical limitations of these studies.”
Huber notes that the “editorial accompanying the studies highlights some of the limitations of each study and notes that they ‘aren’t the final word’ on vitamin D’s role in protecting against COVID-19.”
“For example, the editorial points out that about 50% of participants in the control arm of the Jolliffe et al. [UK] study were using vitamin D alone.”
Analyzing supplementation impact on COVID-19
The initial study was conducted in the UK between May and October 2021. The researchers discovered that the incidence of COVID-19 was unaffected by vitamin D intake. A high prevalence (64.6%) of individuals have inadequate 25-hydroxyvitamin D levels (50 nmol/L).
The researchers note that vitamin D increases the body’s ability to fight off respiratory infections like the influenza A virus.“To prevent COVID-19, CRN encourages following proper public health measures including vaccination, testing, wearing a mask and maintaining social distance as appropriate, as well as optimizing vitamin D levels, which can be achieved through supplementation,” Huber explains.
“This isn’t an either/or situation. It’s a both/and – and those who suggest otherwise are doing the public a disservice.”
Meanwhile, the other experiment, which substituted cod liver oil for low dose (400 IU/day) vitamin D supplementation, was carried out in Norway between November 2020 and June 2021.
For six months, the researchers randomly assigned 34,741 participants to take 5 mL of cod liver oil or 5 mL of a placebo. Once more, the researchers discovered no impact of cod liver oil on any result, including COVID-19, which was validated by a polymerase chain reaction.
Vitamin D deficient individuals
Huber adds that the editorial also notes “these new trials remain compatible with the two large meta-analyses suggesting that vitamin D supplementation may be beneficial for vitamin D deficient individuals.”
The researchers add that supplementing with 1000 to 2000 IU/day of vitamin D could be a secure option for people with insufficient vitamin D levels.“Indeed, meta-analyses of studies conducted since the beginning of COVID-19 largely demonstrate a positive role for higher vitamin D levels in reducing the incidence, severity and mortality from the disease.”
“The editorial makes clear, ‘For those with inadequate vitamin D levels (<50 nmol/L), supplementation with 1000-2000 IU/day could be a safe, simple and affordable way to restore vitamin D levels, improve bone health and take advantage of any possible protective effect against respiratory tract infections.’”
Vitamin D supplementation and safety
Regarding vitamin D’s role and viral infections, it was previously noted in a clinical study that pregnant women who consume fish oil and vitamin D may lower the number of viral croup infections, which frequently manifest themselves in the “barking” cough of the infants and children who may develop them.
However, the French Agency for Food, Environmental and Occupational Health and Safety (ANSES) warned of the risks of vitamin D overload, particularly for infants.
By Nicole Kerr
