Vitamin D metabolite levels in normal children

Area of Science:

• Pediatric Endocrinology
• Nutritional Biochemistry
• Seasonal Health Variations

Background:

• Vitamin D is crucial for children's health, with metabolite levels potentially influenced by environmental factors like season and age.
• Understanding seasonal variations in vitamin D metabolites is essential for assessing children's nutritional status and sun exposure.

Purpose of the Study:

• To investigate the seasonal patterns of key vitamin D metabolites (25(OH)D3, 24,25(OH)2D3, 1,25(OH)2D) in a cohort of normal children.
• To explore the influence of age and multivitamin supplementation on these seasonal variations.

Main Methods:

• Year-round measurement of serum vitamin D metabolites in 174 healthy children.
• Statistical analysis to assess seasonal variations, age-related differences, and the impact of multivitamin intake.
• Comparison of metabolite levels between winter and summer, and between supplemented and non-supplemented children.

Main Results:

• 25-hydroxyvitamin D3 (25(OH)D3) and 24,25-dihydroxyvitamin D3 (24,25(OH)2D3) levels were significantly higher in summer than in winter.
• A notable decrease in 1,25-dihydroxyvitamin D (1,25(OH)2D) was observed in late summer (August-September), inversely correlated with 24,25(OH)2D3.
• Winter 25(OH)D3 levels increased with age, while multivitamin supplementation in winter was associated with lower endogenous 25(OH)D3 and 24,25(OH)2D3 levels.

Conclusions:

• Children exhibit distinct seasonal variations in vitamin D metabolites, with implications for monitoring and supplementation strategies.
• The interplay between age, season, and multivitamin use affects vitamin D metabolite profiles in children.
• Further research may clarify the clinical significance of late summer 1,25(OH)2D reduction and the impact of supplementation on endogenous production.