Hair and serum calcium, iron, copper, and zinc levels during normal pregnancy at three trimesters.

The hair and serum levels of calcium, iron, copper, and zinc levels were measured in a group of 70 healthy pregnant women and in 66 age-matched healthy controls living in the Tianjin city of the People's Republic of China. The study subjects were classified into three subgroups according to gestational age. The hair concentrations were measured by X-ray fluorescence spectrometry, whereas those in sera were established by atomic absorption spectrometry. The hair concentrations of Ca, Fe, Cu, and Zn in the three groups of gravida were lower or significantly lower than those in controls. In sera, the differences did not show statistical significance in most cases. A deficiency of calcium was observed in subjects in the last trimester of gestation. This reinforces the importance of supplementation with calcium during pregnancy.