Measuring vitamin D levels in blood samples
To evaluate vitamin D levels, the scientists used a repository of blood samples. The women identified using the Finnish Maternity Cohort had conveniently also given blood samples as part of their routine prenatal care. Researchers decided to look at the vitamin D levels in these blood samples and measure Vitamin D.
What concentration of vitamin D is considered adequate?
When measuring vitamin D levels, a deficiency was considered any concentration lower than 30 nanomoles per liter (30 nmol/L). Levels above 50 nmol/L were considered normal, and anything between 30-50 nmol/L was considered an insufficiency.