Neonatal Vitamin D Levels in Relation to Risk of Overweight at 7 Years in the Danish D-Tect Case-Cohort Study.

BACKGROUND

Vitamin D level in pregnancy may be associated with risk of overweight in the offspring later in life.

METHODS

In a case-cohort study based on Danish biobanks and registers we examined the association between 25-hydroxy-vitamin D (25(OH)D) level at birth and overweight at 7 years. Cases of overweight (n = 871) were randomly selected among 7-year-old children from the Copenhagen School Health Records Register (CSHRR) with a BMI above the 90th percentile. The cohort (n = 1,311) was a random sample selected among all Danish children born during the same period. Neonatal 25(OH)D was measured in dried blood spots.

RESULTS

25(OH)D3 exhibited the expected seasonal variation. Median level of 25(OH)D3 was 20.6 (11.9-33.3) nmol/l in the overweight group and 23.4 (13.5-34.3) nmol/l in the cohort. We found no association between neonatal 25(OH)D3 level and risk of overweight at age 7 years, neither in the crude model (OR (CI) 1.00 (0.99; 1.00)) nor in a model adjusted for maternal ethnicity, educational level, civil status, parity, season and year of birth, and offspring ponderal index (OR (CI) 1.00 (0.99; 1.01)).

CONCLUSION

Risk of overweight at 7 years of age was not associated with vitamin D level at birth.