Anne Gaml-Sørensen, Nis Brix, Andreas Ernst, Lea Lykke Harrits Lunddorf, Christian Lindh, Gunnar Toft, Tine Brink Henriksen, Onyebuchi A Arah, Cecilia Høst Ramlau-Hansen
BACKGROUND: Season of birth has been associated with age at menarche. Maternal vitamin D levels in pregnancy may explain this effect. We investigated whether the season of first trimester or maternal 25-hydroxyvitamin D3 [25(OH)D3] levels were associated with pubertal timing in children. METHODS: We conducted a follow-up study of 15 819 children born in 2000-03 from the Puberty Cohort, nested in the Danish National Birth Cohort (DNBC). Mean differences in attaining numerous pubertal markers, including a combined estimate for the average age at attaining all pubertal markers, were estimated for low (November-April) relative to high (May-October) sunshine exposure season in the first trimester using multivariable interval-censored regression models...
May 13, 2023: International Journal of Epidemiology