Define Interaction of Vitamin D with other Nutrients?

Vitamin D metabolism is inter-related with calcium, phosphorous, vitamin K and iron.  Let us discuss each of these:

• Calcium: The interaction of vitamin D with calcium has already been discussed earlier. Vitamin D initiates calcium absorption, as well as, activation of protein kinase.
• Phosphorous: Vitamin D increases the activity of brush border alkaline phosphatase, which hydrolyzes phosphate ester bonds allowing phosphorous absorption.
• Vitamin K: An inter-relationship exists between vitamin D and K based on their relationship to the mineral calcium. Vitamin D has an impact on calcium metabolism and vitamin K-dependent proteins bind calcium. The two sites of action of vitamin D .are bone and kidney tissues, where vitamin K-dependent calcium- binding proteins have been identified which regulate the production of crucial enzymes.
• Iron: A decrease in vitamin D has been observed as a result of iron deficiency.