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How does vitamin D help regulate calcium and phosphate levels?
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Endocrine system
The glands of the human endocrine system.
Vitamin D plays a critical role in maintaining calcium and phosphate homeostasis through its active form, calcitriol.12
Mechanisms of Regulation
- Intestinal Absorption: The primary function of calcitriol is to increase the efficiency of dietary calcium and phosphorus absorption in the small intestine, ensuring these minerals enter the bloodstream.13
- Bone Metabolism: Calcitriol interacts with osteoblasts to regulate bone remodeling. When dietary calcium is insufficient, calcitriol—working in concert with parathyroid hormone—stimulates the production of factors that induce the maturation of osteoclasts. These cells release minerals from bone into the circulation to maintain serum levels. Conversely, when calcium needs are met, calcitriol promotes bone formation and mineralization.13
- Hormonal Interaction: Vitamin D production is stimulated by parathyroid hormone in the kidneys. While parathyroid hormone promotes the renal excretion of phosphorus, calcitriol helps balance this by enhancing intestinal phosphorus absorption.1
Deficiencies in vitamin D impair these processes, leading to low serum mineral concentrations and poorly calcified bones, manifesting as rickets in children or osteomalacia in adults.12