According to a study published in the Journal of the American Medical Association (JAMA) Network Open, the VITAL trial data showed that only those with a BMI of 25 had a favorable correlation between vitamin D intake and numerous health outcomes. In the study conducted by researchers from the Brigham and Women′s Hospital, they evaluated whether taking vitamin D or marine omega-3 supplements may lower the chance of acquiring cancer, heart disease, or stroke.

Vitamin D is a crucial component involved in a variety of biological activities, most notably aiding in the body′s absorption of minerals like calcium and magnesium. While the body can produce some vitamin D with the help of sunlight, its deficiency is frequently addressed by using supplements. The initial VITAL experiment was spurred by data from laboratory studies, epidemiologic research, and clinical research that revealed vitamin D may be involved in the onset and development of cancer and cardiovascular disease, according to the report.

As a result, the purpose of this new study was to look into this connection. For the study, the researchers collected and examined data from 16,515 individuals in the original experiment who gave blood samples at baseline (before being randomly assigned to vitamin D) and 2,742 who submitted a follow-up blood sample after two years. They assessed levels of total and free vitamin D as well as a variety of new biomarkers for vitamin D, including its metabolites, calcium, and parathyroid hormone, which aid in the body′s absorption of vitamin D.

The researchers observed that regardless of a person′s weight, taking vitamin D supplements boosted the majority of the biomarkers linked to vitamin D metabolism in that consumer. In contrast, in those with high BMIs, these gains were noticeably less pronounced. They concluded that this study explained why vitamin D supplementation resulted in 30–40% lower rates of cancer deaths, autoimmune diseases, and other outcomes in people with lower BMIs. Hence, they suggested that a more individualized vitamin D dosage could benefit the entire population. 

(Source: https://www.hindustantimes.com/health/high-bmi-could-diminish-vitamin-d-effects-study-101674042951768.html )