[Vitamin D: pathophysiology and clinical applicability in paediatrics]

Area of Science:

• Endocrinology and Metabolism
• Immunology
• Neuroscience

Context:

• Vitamin D traditionally linked to calcium-phosphate metabolism.
• Emerging evidence suggests broader physiological roles due to widespread vitamin D receptors.
• Deficiency is associated with increased risk of infections, autoimmune disorders, diabetes, metabolic syndrome, obesity, and neurological conditions like schizophrenia.

Purpose:

• To review the current understanding of vitamin D's physiology and actions.
• To discuss the challenges and importance of standardizing laboratory measurements of 25(OH) cholecalciferol.
• To explore established and recommended vitamin D levels and intake strategies.

Summary:

• Vitamin D receptors are present in various cells, indicating roles beyond mineral metabolism.
• Vitamin D deficiency is linked to numerous chronic health conditions.
• Standardization of 25(OH) cholecalciferol assays is critical for reliable clinical interpretation and research comparison.
• Optimal physiological vitamin D levels are considered above 20 ng/ml (50 nmol/l).
• Strategies for achieving adequate vitamin D levels, balancing sunlight exposure with skin cancer prevention, are under discussion.

Impact:

• Highlights the need for standardized vitamin D testing methods.
• Underscores the importance of maintaining adequate vitamin D levels for overall health.
• Suggests a re-evaluation of vitamin D's role in primary care and public health initiatives.
• Identifies areas for future research regarding vitamin D's multifaceted functions and optimal supplementation.