Researchers have used UK Biobank data to reveal more 30 genes that can influence vitamin D levels. While some are previously known for their vitamin D association, others are being identified for the first time. Although sunshine can trigger vitamin D production in our bodies, and a few foods contain some vitamin D, there are problems with low levels of vitamin D in many nations. A lack of vitamin D can lead to a variety of serous health problems. The findings have been reported in Nature Communications.
In this study, the researchers assessed genetic data for more than 330,000 volunteers in the UK Biobank, and used satellite data and home address information for these individuals to determine how much UVB they would be exposed to over a five month period prior to the date of a vitamin D measurement. The investigators were able to quantify environmental influences on vitamin D, and decipher how genetics and sunshine exposure might be linked.
This effort showed that about 300 variations in genes can be associated with how high a person's vitamin D levels are.
Some of the genes that have been newly linked to vitamin D levels are connected the body’s natural daily cycle–the circadian rhythm. There might be relationships between a person’s circadian rhythm, vitamin D levels, and an innate seasonal rhythm. While there is no known seasonal rhythm in humans, many animals have one, such as hibernation.
Other genes that were linked to vitamin D levels included some related to lipid and steroid metabolism. So, vitamin D levels could be connected to body mass index (BMI) as well, with people who are vitamin D deficient being more likely to have a higher BMI. BMI can vary by season, and vitamin D variation may help explain that finding.
Other vitamin D-linked genes included some that function to help remove substances like drugs or hormones from the body.
The work also shows the potential of personalized medicine, since an individual’s genetics and sunlight exposure could be analyzed to determine their risk of low vitamin D, and their potential need for supplementation recommendations.
"Our study highlights the complexity of the relationship between our genes and the surrounding environment,” said first study author Dr. Rasha Shraim, a postdoctoral researcher at Trinity College. “We can learn a lot about human health from studying them together. In this case, we find a link between vitamin D and circadian rhythm, and this also raises interesting new research questions.”
"Our genetic makeup is shaped by millions of years of interaction with the environment, so it is only logical that genetic studies should account for the environment but doing so is often challenging in practice” said senior study author Professor Lina Zgaga of Trinity College. "A surprisingly small number of gene-environment interactions have been described to date, so several gene-UVB interactions we uncovered are noteworthy and highlight how genetic and environmental factors are deeply intertwined.”
Sources: Trinity College Dublin, Nature Communications