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Plasma 1.25-dihydroxyvitamin D concentrations in preterm infants
Insights
Preterm infants can produce high levels of 1.25-dihydroxyvitamin D, a crucial vitamin D metabolite. This study tracked these levels in preterm infants, finding they exceeded adult concentrations without signs of rickets.
Area of Science:
- Pediatrics
- Endocrinology
- Nutritional Science
Background:
- Preterm infants face unique nutritional challenges.
- Vitamin D metabolism is critical for bone health in infants.
- Understanding vitamin D metabolite levels in preterm infants is essential.
Purpose of the Study:
- To measure 1.25-dihydroxyvitamin D concentrations in preterm infants.
- To compare these levels with those in adults.
- To assess potential correlations with clinical and biochemical parameters.
Main Methods:
- Measured 1.25-dihydroxyvitamin D in 10 preterm infants over 12 weeks.
- Monitored nutritional intake (parenteral and enteral feeding, vitamin D3 supplementation).
- Assessed clinical, chemical, and radiological signs of rickets.
Main Results:
- 1.25-dihydroxyvitamin D levels were highly variable but generally high in preterm infants.
- Mean levels at 6, 9, and 12 weeks were significantly higher than in adults.
- No correlation found between 1.25-dihydroxyvitamin D and 25-hydroxyvitamin D, calcium, phosphorus, or alkaline phosphatase.
Conclusions:
- Preterm infants demonstrate a capacity for producing elevated plasma 1.25-dihydroxyvitamin D.
- High levels were observed despite standard vitamin D supplementation and without rickets.
- Further research may explore the implications of these findings for preterm infant health.
Abstract:
1.25-Dihydroxyvitamin D concentrations were measured in 10 preterm infants (mean gestational age 29 weeks, range 26-32; mean birthweight 1226 g, range 980-1700). Total parenteral nutrition was begun after birth and partial enteral feeding was started at 1 week of age. Total enteral feeding was achieved at a mean age of 26 days (range 16-47). The daily vitamin D3 intake was about 400 I. U. No clinical, chemical or radiological signs of rickets were observed. The mean 1.25-dihydroxyvitamin D concentration +/- SEM was 103.2 +/- 24.0 pmol/l at 1 week (range 9.6-252.0), 141.6 +/- 26.4 at 3 weeks (range 31.2-324.0), 153.6 +/- 21.6 at 6 weeks (range 67.2- 256.8), 165.6 +/- 24.0 at 9 weeks (range 74.4-307.2) and 153.6 +/- 21.6 at 12 weeks (range 76.8-268.8) postnatal age. The mean values at 6, 9 and 12 weeks were significantly higher (p resp. less than 0.01, less than 0.002 and less than 0.005) than in adults (88.8 +/- 7.2; n = 27). 1.25-Dihydroxyvitamin D concentrations were highly variable and did not correlate with 25-hydroxyvitamin D concentrations, plasma calcium and phosphorus concentrations and plasma alkaline phosphatase levels, nor with illness nor postnatal age. The data demonstrate that preterm infants are capable of producing high plasma levels of 1.25-dihydroxyvitamin D.