For the last 80 years we have focused on the link between vitamin D and calcium – vitamin D is necessary for calcium absorption and its deficiency leads to rickets. But this is just the visible part of the iceberg.
The bottom part of the iceberg is cell cycle and immune regulation, as vitamin D is involved in gene expression processes. This less known role actually accounts for about 85% of the metabolism of vitamin D everyday in our body (1).
This means that, depending on which type of cells it affects, vitamin D inadequacy can be involved in many other dysfunctions including cardiovascular diseases and cancer: