Covid and Vitamin D

Adapted from Scientific Reports 2022 doi:10.1038/s41598-022-24053-4 and BMJ 3 June 23 and BMJ 1 Jul 23.

A USA retrospective study on veterans found that vitamin D supplementation reduced Covid infection by 20-28% and mortality rates by 25-33%.

Black veterans got more benefit than white veterans, possibly because darker skins absorb less vitamin D from the sun.

Vitamin D3 supplementation was more effective than Vitamin D2 supplementation.

Covid infection has been shown in a Danish study to have no impact on the later appearance of Type One Diabetes.

During the pandemic 90% of Danish children were tested for Covid, often on multiple occasions. There was no increase in type one diabetes in the children who had been infected compared to those who tested negative throughout.

Covid infection, meanwhile, has not yet settled into a seasonal pattern like influenza. Most countries are seeing more frequent but less severe infections than during the pandemic. This is due to the speed of mutation of the spike protein which is evolving twice as fast as the usual influenza viruses and ten times faster than seasonal coronaviruses that cause runny noses, coughs and sore throats.

Metformin users can feel pleased that yet another advantage to taking the drug has been found. If taken during the acute phase of Covid infection, Metformin led to 40% fewer cases of long Covid over a ten month period. Metformin was given within 3 days of a positive Covid test and was continued for two weeks. This was a placebo controlled trial.

Vitamin D supplementation in a double blinded randomised controlled study from 2014 to 2020 in Australia was found to reduce the risk of major cardiovascular events.

Over 21 thousand participants aged 60-84 years of age were randomly assigned to have monthly oral doses of Vitamin D3 60,000 IU or a placebo for five years. The researchers then measured how many heart attacks, strokes, and coronary revascularisation procedures occurred.

A reduction in cardiac and revascularisation events was most clearly seen in those participants who were taking the vitamin D and particularly in those were already on drugs for the cardiovascular system at the start of the study. The number needed to treat to avoid an event was one in 172. There was no difference in the number of strokes between the groups.