Why Vitamin D Levels Don’t Rise Even If You Take It Regularly: A New Genetic Explanation 0 7

Vitamin D is essential for the proper functioning of almost all organs and systems. For example, it affects calcium absorption (which is especially important for the elderly) and is necessary for the normal functioning of the immune system. Vitamin D is also required for the proper functioning of the heart, strong memory, good mood, and this is far from an exhaustive list.

However, doctors strongly recommend not to buy vitamin D supplements just like that. An excess can be worse than a deficiency, so first tests and consultation, and then a trip to the pharmacy.

Moreover, it is important to consider the exact dosage and your individual characteristics. This is once again confirmed by a recent study by scientists from the Netherlands, the United Kingdom, Denmark, Austria, and Germany. Experts managed to identify at least 30 new genes that influence the absorption and functioning of vitamin D in the body.

In their work, the scientists analyzed medical data from over 30,000 participants, all necessary information was provided by the UK Biobank. It was already known that sunlight stimulates the production of vitamin D, so its concentration is usually at a maximum in summer and at a minimum in winter. The researchers decided to deepen this knowledge: the authors used satellite data to obtain information on daily UV radiation levels in the region where each participant lived. Blood concentrations of vitamin D after testing were also taken into account.

This allowed the experts to identify several dozen genetic variants that regulate the level of vitamin D in the body. Here are the main findings of the scientists.

Several "vitamin" genes are associated with the circadian rhythm. It is known that many mammals have seasonal rhythms—naturally built-in metabolic cycles, such as molting or hibernation, which affect vitamin absorption. Experts believe that the human body operates on the same principle.

Many of the identified genes are important for the metabolism of steroids and lipids. This indicates that BMI and vitamin D levels may be interconnected: people with vitamin D deficiency often have a higher BMI, and vice versa. It is believed that BMI changes with the seasons: it is higher in winter than in summer.

Some genes code for enzymes that are important for the excretion of a wide range of molecules, such as drugs, hormones, or vitamin D. Sometimes this process is reversible, which led experts to suggest that some forms of vitamin D metabolites may be converted back into its active form.

Thus, the level of vitamin D in the body depends on individual genetic characteristics, metabolism, weight, and the time of year! For this reason, you may require a higher dosage in winter than in summer.

Experts are confident that their research can serve as a guide for revising vitamin D intake recommendations. They will continue to work in this direction to learn as much as possible about the impact of genetics on its absorption.