Introduction:
Vitamin D plays a crucial role in calcium homeostasis and bone metabolism. Deficiency in vitamin D is linked to impaired bone mineralization, increased fracture risk, and osteoporosis. Despite growing global awareness, vitamin D insufficiency remains highly prevalent across different age groups, particularly in the elderly and postmenopausal women. This study aims to evaluate the impact of vitamin D levels on bone health outcomes, investigate the effectiveness of supplementation in at-risk populations, and highlight the importance of preventive strategies in clinical practice.
Methods:
A systematic review was conducted, including randomized controlled trials (RCTs) and observational studies published between 2015 and 2024. Databases searched included PubMed, Scopus, and Cochrane Library. Studies assessing serum 25-hydroxyvitamin D levels and outcomes such as bone mineral density (BMD), fracture incidence, or bone turnover markers were included. Data were extracted on participant demographics, intervention type, duration, baseline vitamin D status, and clinical outcomes. A qualitative synthesis was performed to identify trends and evaluate clinical significance.
Results:
Twenty-eight studies with a total of 15,342 participants were included. Low serum vitamin D (<20 ng/mL) was consistently associated with reduced BMD and a higher risk of osteoporotic fractures. Supplementation, particularly when combined with calcium, significantly improved BMD in postmenopausal women and elderly men. Fracture risk reduction ranged from 12% to 25%, especially in participants with baseline deficiency. Compliance, dosage, duration of supplementation, and initial vitamin D status were key determinants of efficacy.
Conclusion:
Maintaining adequate vitamin D status is essential for bone health, particularly in high-risk populations. Vitamin D supplementation effectively improves BMD and reduces fracture risk when appropriately administered. Early detection of deficiency and individualized supplementation strategies are recommended to optimize skeletal outcomes and support long-term musculoskeletal health.
