What you did not know about Vitamin D

Vitamin D is a fat-soluble vitamin that is naturally present in very few foods, added to others, and available as a dietary supplement. It is also produced endogenously when ultraviolet rays from sunlight strike the skin and trigger vitamin D synthesis. Vitamin D promotes calcium absorption in the gut and maintains adequate serum calcium and phosphate concentrations to enable normal mineralization of bone and to prevent hypocalcemic tetany. It is also needed for bone growth and bone remodeling by osteoblasts and osteoclasts. Without sufficient vitamin D, bones can become thin, brittle, or misshapen. Vitamin D sufficiency prevents rickets in children and osteomalacia in adults. Together with calcium, vitamin D also helps protect older adults from osteoporosis.

Vitamin D has other roles in the body, including modulation of cell growth, neuromuscular and immune function, and reduction of inflammation. Many genes encoding proteins that regulate cell proliferation, differentiation, and apoptosis are modulated in part by vitamin D.

Vitamin D Deficiency

Vitamin D deficiency can result from inadequate exposure to sunlight, malabsorption and accelerated catabolism from certain medications.
In children, vitamin D deficiency can result in rickets which presents as bowing of legs; in adults, it results in osteomalacia or osteoporosis.

Signs and Symptoms

Vitamin D deficiency is often clinically silent. Manifestations are as follows:

• Children are often found to have started walking late or prefer to sit down for prolonged periods.
• Adults can experience chronic muscle aches and pains.

Physical findings in severe vitamin D deficiency are as follows:

• In children, bowing in the legs.
• In adults, periosteal bone pain, best detected with firm pressure on the sternum or tibia

Vitamin D Toxicity

Vitamin D toxicity is rare. It is caused by supplementing with high doses of vitamin D rather than sunlight. Hypercalcemia is a strong indication of vitamin D toxicity, noted with an increase in urination and thirst. If hypercalcemia is not treated, it results in excess deposits of calcium in soft tissues and organs such as the kidneys, liver, and heart, resulting in pain and organ damage. Research has indicated that Vitamin D toxicity is closely related to a depletion of Vitamin K and that repletion of Vitamin K allows individuals to supplement with higher doses of Vitamin D without the negative calcium-related side effects.

Vitamin D Formulations

Which is better: Vitamin D2 or D3?
-Ergocalciferol (vitamin D2) and cholecalciferol (vitamin D3) are not bioequivalent and should not be considered as interchangable.

-Studies indicate that ergocalciferol (vitamin D2) is much less potent and has a shorter duration of action than cholecalciferol.

Subscribe to our newsletter, like our page on Facebook and follow us on Twitter.