Shifts in the Distribution of Births by Gestational Age: United States, 2014-2022
National Vital Statistics Reports Volume 73, Number 1 (CDC)
Joyce A. Martin, and Michelle J.K. Osterman, M.H.S.
 Download the PDF from VitaminDWiki
Finland appears to have the highest Vitamin D level in the world
After years of adding vitamin D, Finland now has 38 ng levels - March 2022
95 percent of pregnant women in Finland took vitamin D – PHD Dissertation Dec 2019
Finland's preterm birth rates have DECREASED recently
- Preterm birth in the Nordic countries-Capacity, management and outcome in neonatal care https://doi: 10.1111/apa.16753
- 5.8% were preterm, 0.83% very preterm, 0.28% were extremely preterm
- Prevalence of preterm birth in Scandinavian countries: a systematic review and meta-analysis - Oct 2023 PDF