Which of the following is NOT a function of vitamin D in the human body?

• A. Enhancing intestinal absorption of calcium and phosphorus
• B. Supporting bone mineralization and remodeling
• C. Regulating gene expression through the vitamin D receptor (VDR)
• D. Serving as a primary antioxidant that protects cell membranes from lipid peroxidation

Answer: (D)

Verified step by step guidance

1. Step 1: Understand the primary functions of vitamin D in the human body. Vitamin D mainly helps regulate calcium and phosphorus levels, supports bone health, and influences gene expression through the vitamin D receptor (VDR).
2. Step 2: Review each option given in the problem and compare it to the known functions of vitamin D. For example, enhancing intestinal absorption of calcium and phosphorus is a well-established role of vitamin D.
3. Step 3: Recognize that supporting bone mineralization and remodeling is directly related to vitamin D's role in maintaining bone health by regulating calcium and phosphorus balance.
4. Step 4: Understand that vitamin D regulates gene expression by binding to the vitamin D receptor (VDR), which influences various biological processes.
5. Step 5: Identify that serving as a primary antioxidant protecting cell membranes from lipid peroxidation is not a recognized function of vitamin D. This role is typically associated with other nutrients like vitamin E.