In a collaborative study by the Universities of Surrey and Brighton, researchers investigated the impact of vitamin D supplements – D2 and D3 – taken daily over a 12-week period on the activity of genes in people’s blood.
Those involved in the research, contrary to widespread opinion, found significant differences between the two vitamin D supplements, as they discovered that vitamin D2 leaves a questionable mark on human health.
“Vitamin D3 appears to stimulate the type I interferon signaling system in the body – a key part of the immune system that provides a first line of defense against bacteria and viruses. Thus, a healthy vitamin D3 status may help prevent viruses and bacteria from gaining a foothold in the body,” said Professor Colin Smith, lead-author of the study from the University of Surrey.
“Our study suggests that it is important that people take a vitamin D3 supplement, or suitably fortified foods, especially in the winter months.”
Although some foods are fortified with vitamin D, like some breakfast cereals, yogurts, and bread, few naturally contain the vitamin. Vitamin D3 is produced naturally in the skin from exposure to sunlight or artificial ultraviolet UVB light, while some plants and fungi produce vitamin D2.
Many people have insufficient levels of vitamin D3 because they live in locations where sunlight is limited in the winter, like the UK. The Covid-19 pandemic has also limited people’s natural exposure to the sun due to people spending more time in their homes.