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Updated: Feb 24, 2026
Transcutaneous Microcirculatory Imaging in Preterm Neonates
Published on: December 31, 2015
[Neonatal intoxication to vitamin D in premature babies: A series of 16 cases]
M Vierge1, S Laborie2, A Bertholet-Thomas1
1Centre de référence des maladies rénales rares, hôpital Femme-Mère-Enfant, 59, boulevard Pinel, 69677 Bron, France.
Insights
Vitamin D overdose in preterm infants can cause serious health issues like nephrocalcinosis and hypercalcemia. Early detection and management are crucial for recovery and preventing long-term complications.
Area of Science:
- Neonatal Medicine
- Pediatric Nephrology
- Endocrinology
Background:
- Preterm neonates are susceptible to vitamin D deficiency, with varying international guidelines for supplementation (400-1000 IU/day).
- Optimal target levels for 25-hydroxyvitamin D (25-D) are not well-defined, ranging from 50-75 nmol/L to 120 nmol/L.
Purpose of the Study:
- To investigate the clinical and biological characteristics of preterm infants experiencing vitamin D (25-D) overdose.
- To identify symptoms and outcomes associated with 25-D overdose in this vulnerable population.
Main Methods:
- Retrospective review of clinical and biological data from 16 premature infants (born <35 weeks gestational age) with suspected 25-D overdose.
- Data analysis included gestational age, birth weight, symptoms, vitamin D dosage, and 25-D and 1-25 vitamin D levels.
Main Results:
- Infants presented with nephrocalcinosis (37%), hypercalcemia (44%), or hypercalciuria (19%) at a median age of 36.6 weeks.
- Elevated 25-D levels (median 210 nmol/L) and 1-25 vitamin D levels (median 370 pmol/L) were observed.
- Withdrawal of vitamin D led to normalization of 25-D levels in 10 patients and improvement of nephrocalcinosis in 10 of 12 patients.
Conclusions:
- Vitamin D overdose should be considered in preterm infants presenting with nephrocalcinosis, hypercalcemia, or hypercalciuria.
- Further research is needed to determine the precise prevalence of vitamin D deficiency and overdose in preterm infants.
- Long-term effects of vitamin D imbalances on bone, kidney, and brain development require evaluation.
Introduction:
Preterm neonates are particularly at risk of vitamin D (25-D) deficiency. To prevent rickets and osteopenia in this population, international guidelines vary between 800 and 1000IU per day of vitamin D in Europe and recommend 400IU per day in the USA. Target levels of circulating 25-D are not well identified, with the lower target level 50-75nmol/L and the upper target level probably 120nmol/L.
Methods:
Between 2013 and 2015, 16 premature infants (born<35WG) were referred to pediatric nephrology clinics because of symptoms secondary to 25-D overdose during the neonatal period. Clinical and biological data were retrospectively reviewed to better define this population. The results are presented as the median (range).
Results:
Gestational age was 27 (24-35)WG with a birth weight of 810 (560-2120)g. Nephrocalcinosis was the initial symptom in 37% of cases, hypercalcemia in 44%, and hypercalciuria in 19%. Daily vitamin D doses were 333 (35-676)IU. Age and body weight at initial symptom were 36.6 (27.6-47.6)WG and 2300 (640-3760)g, respectively. The 25-D level at the time of the first dosage was 210 (119-350)nmol/L and the 1-25 vitamin D level was 370 (245-718)pmol/L (local normal values for age<240). During follow-up, 12 patients displayed nephrocalcinosis, ten hypercalciuria, and three hypercalcemia. The 25-D level normalized in ten patients within 10 (3-32)months after vitamin D withdrawal. Nephrocalcinosis improved in ten of 12 patients, within 12 (3-30)months. Vitamin D could be readministered in ten patients. When searched (n=3), no CYP24A1 mutation was identified in two patients, but was identified in the heterozygous state in one.
Conclusion:
A 25-D overdose should be systematically ruled out in the presence of nephrocalcinosis, hypercalcemia, and/or hypercalciuria during infancy in children born preterm. Studies are required to assess the exact frequency of 25-D deficiency and overdose in this population, as well as to evaluate the potential deleterious effects of this imbalance on bone, kidney, and brain development.
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