[Neonatal vitamin D status and calcium-phosphorus homeostasis in the third week of life].
OBJECTIVE
Assessment of vitamin D status and calcium -phosphorus homeostasis in term newborns before routine supplementation.


METHODS
Calcidiol (25OHD), calcium, phosphorus and alkaline phosphatase in serum and Ca (urine)/creatinine (urine) ratio (mg/mg), P (urine)/creatinine (urine) ratio (mg/mg) and tubular phosphate reabsorption rate (TRP= [1-(P(urine) / P(serum). creatinine serum/urine)].100%) in 3rd week of life in 56 appropriate for gestational age term neonates was measured. First group contains 35 newborns (62.5%) with normal 25OHD values and second group 21 newborns (37.5%) with hypovitaminosis D (25OHD < 11 ng/ml).


RESULTS
Mean 25OHD concentration was 15.23 ng/ml + 8.57 ng/ml. Maternal vitamin D supplementation (10 ug/day) for more than 4 months of pregnancy was similar in both groups (55.9% vs. 52.4%) (p>0.05). There were 51.43% breastfed newborns in group one and 85.71% in group two (p=0.009). Median 25OHD concentration in breastfed newborns was 11.2 ng/ml and 18.5 ng/ml in formula fed babies (p=0.017). There were no statistical differences between groups in calcium (2.44 vs. 2.41 mmol/l), phosphorus (2.27 vs. 2.22 mmol/l) and alkaline phosphatase (261 vs. 266 U/L) blood concentration and Ca (urine)/creatinine (urine) ratio (0,34 vs. 0,25mg/mg) and TRP (86% vs. 88%) (p>0.05). The P (urine) /creatinine (urine) ratio in the first group was 2.3mg/mg and 1.42 mg/mg in the second group (p=0.048).


CONCLUSIONS
Neonatal vitamin D stores in the 3rd week of life are not more dependent on maternal vitamin D supplementation during pregnancy. Breastfed infants are at greater risk of hypovitaminosis D than formula fed infants, therefore earlier vitamin D supply should be considered. The hypovitaminosis D has no influence on basic parameters of Ca-P homeostasis in the 3rd week of life.
Czech-Kowalska
Justyna
J
Klinika Patologii Noworodka, Instytut Pomnik Centrum Zdrowia Dziecka, Al. Dzieci Polskich 20, 04-736 Warszawa, Poland. justynakowalska@poczta.fm
Dobrzanska
Anna
A
Janowska
Joanna
J
Pleskaczynska
Agata
A
Niezgoda
Anna
A
Golkowska
Malgorzata
M
Witwicki
Jacek
J
Gruszfeld
Dariusz
D
Jedrzejczak
Anna
A
D000469:Alkaline Phosphatase / Q000378:metabolism; D015415:Biomarkers / Q000378:metabolism; D002112:Calcifediol / Q000097:blood / Q000652:urine; D002118:Calcium / Q000097:blood / Q000378:metabolism* / Q000652:urine; D003404:Creatinine / Q000097:blood / Q000652:urine; D005260:Female; D006706:Homeostasis; D006801:Humans; D007231:Infant, Newborn / Q000097:blood / Q000378:metabolism* / Q000652:urine; D007687:Kidney Tubules, Proximal / Q000378:metabolism; D008297:Male; D010710:Phosphates / Q000378:metabolism; D010758:Phosphorus / Q000097:blood / Q000378:metabolism* / Q000652:urine; D011044:Poland; D014808:Vitamin D Deficiency / Q000097:blood / Q000378:metabolism* / Q000652:urine
D015415:Biomarkers; D010710:Phosphates; D010758:Phosphorus; D003404:Creatinine; D000469:Alkaline Phosphatase; D002112:Calcifediol; D002118:Calcium