Vitamin D

What is it?

Vitamin D refers to several related fat soluble vitamins variants all of which are sterol substances. The most common is cholecalciferol (vitamin D3) found in animal products and fish oils and is identical to that produced in the human body. Ergocalciferol (vitamin D2) is the major synthetic form of provitamin D and is usually found in supplements.

Food sources.

Small amounts are found in fatty fish such as herring, salmon, tuna and sardines, beef and liver, butter, eggs and fortified foods such as margarine and milk.

Deficiency signs.

These may include muscle weakness, joint swelling and pain (rickets), bone pain, increased susceptibility to infections and osteoporosis.

Main actions.

Regulation of calcium and phosphorus levels.

Bone health.

Immune modulation - it enhances immune response to both viral and bacterial agents..

Clinical use.

The prevention and treatment of deficiency states.

Hypoparathyroidism.

Osteoporosis.

Psoriasis.

Improved musculoskeletal strength in the elderly.

Important interactions.

Vitamin D Levels and absorption may be reduced with lipid lowering agents, mineral oils and corticosteroids.

Vitamin D may reduce the effectiveness of calcium channel blockers.