As you probably know, vitamin D is a fat-soluble vitamin, which means that it is absorbed, transported, metabolized and stored like fat. And while you probably know that this means that you need to take your vitamin D supplement with a source of fat so that it is absorbed properly, what you probably don’t know is that it affects the state of vitamin D more perhaps. surprising way. *
Because vitamin D is fat-soluble, it is stored in body fat, explains board-certified endocrinologist Brittany Henderson, PhD. So, simply put, the more body fat a person has, the more vitamin D is stored in that body fat. , leaving less vitamin D in circulation throughout the body (and this means that people with higher body fat levels are more likely to reach a deficiency when testing their serum D levels).
As mbg nutrition scientist and director of scientific affairs, Dr. Ashley Jordan Ferira, RDN explains, “less serum vitamin D [aka, 25(OH)D]Circulating in our blood means that less D is available to our kidneys and other target tissues to convert it into its active, hormonal form for its pleiotropic actions throughout our body. “
Ferira goes on to say: “And keep in mind that this is just one way in which obesity can compromise the status of vitamin D and its ability to perform its widespread work in the muscles of bones, immune cells, brain, liver, etc. .n. ”* This study now shows that there are other mechanisms in the relationship between body composition (how much fat relative to pure tissue someone has) and their status and vitamin D needs.
The other mechanism with the strongest science behind it: Volumetric dilution, which simply means that obese people consume (from diet, drinks, supplements) or produce from the sun, is simply more diluted in the body, which then contributes to lowering serum status of vitamin D in general. Based on this, researchers suggest that vitamin D recommendations really should be based on body size, not “universal for all.”
Another mechanism, although still fully developed through research: That obese people experience an increase in circulating levels of calcitriol, the active hormonal form of vitamin D in the body, which then “excludes” the production of 25-hydroxyvitamin D, or 25 (OH) ) D, which is the form of vitamin D that doctors measure when performing a blood test to assess vitamin D levels. As a result, people with higher amounts of body fat have a lower vitamin D status when tested. . *
As Ferira concludes, “whether sequestration into adipose tissue, dilution to body size, or feedback feedback to circulating levels of vitamin D — or all three — obesity adds nuance to the vitamin D status equation, so it is time to talk more about it. “