EC Orthopaedics

Review Article Volume 16 Issue 7 - 2025

Focus on an Individualized Vitamin D Dosage: Physiological Mechanisms, Regulatory Factors and Clinical Implications

Rosini Sergio1, Molfetta Francesco2, Rosini Stefano3 and Molfetta Luigi4

1Biomaterial Research Center, Livorno, Italy

2Smile-Restyle, Livorno, Italy

3DINOGMI Department, School of Medical and Pharmaceutical Sciences, Research Center of Osteoporosis and Osteoarticular Pathologies, University of Genoa, Genoa, Italy

4DISC Department, School of Medical and Pharmaceutical Sciences, Research Center of Osteoporosis and Osteoarticular Pathologies, University of Genoa, Genoa, Italy

*Corresponding Author: Molfetta Luigi, Professor, DISC Department, School of Medical and Pharmaceutical Sciences, Research Center of Osteoporosis and Osteoarticular Pathologies, University of Genoa, Genoa, Italy.
Received: September 19, 2025; Published: November 26, 2025




Background: Vitamin D (Vit D) plays a pivotal role in calcium-phosphate homeostasis, skeletal integrity, and numerous extra-skeletal functions via its active metabolite, calcitriol (1,25(OH)₂D). However, defining an optimal supplementation dosage remains challenging due to interindividual variability.

Objective: To examine the physiological, biochemical, and hormonal determinants influencing vitamin D requirements, with emphasis on calcium absorption efficiency, PTH regulation, leptin signaling, and fibroblast growth factor-23 (FGF-23) interactions.

Methods: Narrative synthesis of physiological mechanisms and published clinical data, focusing on the interplay between vitamin D metabolism, calcium balance, and endocrine modulators.

 Keywords: Vitamin D; 25-Hydroxyvitamin D; Calcitriol; Parathyroid Hormone; Calcium Absorption; Leptin; FGF-23; Osteoporosis

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Molfetta Luigi., et al. “Focus on an Individualized Vitamin D Dosage: Physiological Mechanisms, Regulatory Factors and Clinical Implications”. EC Orthopaedics  16.7 (2025): 01-06.

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