08/08/2025
1. Skin:
When skin is exposed to ultraviolet B (UVB) radiation from sunlight, a cholesterol derivative called 7-dehydrocholesterol is converted into previtamin D3, which is then converted to vitamin D3 (cholecalciferol).
2. Liver:
Vitamin D3 travels to the liver, where it’s converted to 25-hydroxyvitamin D (25(OH)D), also known as calcidiol.
3. Kidney:
25(OH)D then travels to the kidneys, where it’s converted into the biologically active form of vitamin D, 1,25-dihydroxyvitamin D (1,25(OH)2D), also known as calcitriol.
While the skin and kidneys are the primary organs involved, other tissues like the intestines, parathyroid glands, and immune cells can also convert vitamin D precursors into their active form, although to a lesser extent.
Vitamin D production in the skin under the influence of sunlight (UVB) is maximized at levels of sunlight exposure that do not burn the skin.
It aids in the absorption of calcium and phosphorus, which are crucial minerals for building and maintaining strong bones. By promoting calcium deposition and regulating bone remodeling, vitamin D helps in preventing conditions like osteoporosis and fractures. Studies have indicated that maintaining adequate levels of vitamin D can enhance immune function, resulting in a lower susceptibility to illnesses.
Conditions that affect the gut and digestion, like celiac disease, chronic pancreatitis, Crohn’s disease, and cystic fibrosis, can reduce vitamin D absorption.
One common mistake people make while consuming Vitamin D supplements is underestimating its combination with zinc. Zinc transforms cholesterol into Vitamin D, thus aiding in ensuring its sufficient levels.
