Vitamin D2 Supplements May Lower Levels of More Potent Vitamin D3, Study Finds
A new study published today indicates that supplementing with vitamin D2 may reduce levels of vitamin D3 in the body, potentially impacting overall health benefits.
Researchers from the University of Surrey in the U.K., collaborating with the John Innes Centre and the Quadram Institute Bioscience in Norwich, England, analyzed 11 randomized controlled trials encompassing 655 adults. Their findings, published in Nutrition Reviews, revealed that individuals taking vitamin D2 supplements consistently exhibited lower vitamin D3 levels compared to those who did not. Vitamin D is crucial for bone health, immune function, and potentially reducing the risk of chronic diseases.
“Vitamin D supplements are important, especially between October and March, when our bodies cannot make vitamin D from sunlight in the U.K.,” stated Emily Brown, a Ph.D. research fellow from the University of Surrey’s Nutrition, Exercise, Chronobiology & Sleep Discipline. “However, we discovered that vitamin D2 supplements can actually decrease levels of vitamin D3 in the body, which is a previously unknown effect of taking these supplements. This study suggests that, subject to personal considerations, vitamin D3 supplements may be more beneficial for most individuals over vitamin D2.” Previous research, including a study published in Frontiers in Immunology, has demonstrated that vitamin D3 is more effective at boosting the immune system than its D2 counterpart. Understanding the differences between these forms is vital as many foods are now fortified with vitamin D.
Professor Colin Smith, who led the earlier University of Surrey study, explained, “We have shown that vitamin D3, but not vitamin D2, 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.” The researchers acknowledge limitations in the analysis, including variations in study duration and dosage, and call for further investigation to determine if these findings will alter medical advice regarding vitamin D supplementation. You can learn more about Vitamin D from the National Institutes of Health.
Researchers emphasized the need for additional studies to fully understand the distinct effects of vitamin D2 and D3 on the body and to inform future public health recommendations.
