Vitamin D


Vitamin D is a collective term used to describe a few related fat-soluble compounds.

Also known as calciferol, vitamin D comes in two main dietary forms:

  • Vitamin D2 (ergocalciferol). This form is found in mushrooms and some plants.
  • Vitamin D3 (cholecalciferol). This form is found in animal-sourced foods, such as eggs and fish oil, and produced when your skin is exposed to sunlight.

SUMMARYDietary vitamin D can be classified as vitamin D2, which is found in mushrooms and plants, and vitamin D3, which is found in animal-derived foods.

Role and function of vitamin D

Vitamin D has numerous roles and functions, but only a few are well researched. These include the following:

  • Bone maintenance. Vitamin D regulates the circulating levels of calcium and phosphorus, which are the most important minerals for bone growth and maintenance. It promotes the absorption of these minerals from your diet.
  • Immune system regulation. It also regulates and strengthens your immune system function (23Trusted Source).

Once absorbed into the bloodstream, your liver and kidneys change calciferol into calcitriol, which is the biologically active form of vitamin D. It can also be stored for later use in the form of calcidiol.

Vitamin D3 is more efficiently converted into calcitriol than vitamin D2 (24Trusted Source25Trusted Source).

SUMMARYOne of the most important functions of vitamin D is the maintenance of calcium and phosphorus levels in blood. It benefits bone health by promoting the absorption of these minerals.