Recent research has indicated that the benefits of taking vitamin D supplements may vary depending on an individual's weight. According to a study published in JAMA Network Open, people with a lower body mass index (BMI) of less than 25 had a 30-40% reduction in cancer, cancer deaths and autoimmune diseases when taking vitamin D supplements, while those with higher BMIs had only a small benefit. Although the reason for this is not known, it is suggested that those with higher adiposity levels store more vitamin D, or that adipose tissue suppresses enzymes and receptors that are responsible for vitamin D's effectiveness in the body.
Emma Laing, director of dietetics at the University of Georgia and a national spokesperson for the Academy of Nutrition and Dietetics, stated that it is important to consult with a doctor before taking any vitamin D supplements. Certain groups of people, such as competitive athletes and those serving in the military, may require supplements if their physical performance demands make it difficult to meet their nutrition needs from food alone. Additionally, those who have limited food choices, a diagnosed deficiency, or take medications that affect appetite or interfere with nutrient digestion and absorption may need to take supplements.
It is important to note that taking too much of a vitamin D supplement can have side effects, and therefore consulting with a doctor before taking any supplements is advised.