It has a critical role in regulating calcium and phosphorus absorption to improve bone mineral density, bone mass, and reduce fracture risk. Another primary function is its role in boosting immunity. Vitamin D has been also linked to improved heart health and reduced risk of cardiovascular diseases. It also plays a role in insulin sensitivity, insulin resistance and appetite regulation.

Vitamin D plays a major role in neurotransmitter pathways to make serotonin and dopamine, hence why supplementation improves mood, anxiety and depression, and even helps in the progress of patients with MS.