Study 1 was carried out in the setting of an antenatal clinic administered from a primary care center in Borlänge, a Swedish middle-sized industrial town at the 60:th parallel in Sweden. The investigators chose an initial study period in late spring to reflect the effects of the dark season with little ultraviolet B radiation that affects vitamin D production. Study 1 was carried out in a short period of time. The recruitment was performed in a retrospective design in order to neglect the seasonal effects of ultraviolet B radiation. Study 1 was carried out in year 2010. It was a cross sectional baseline study of blood levels of vitamin D measured as 25-hydroxyvitamin D (25-OHD) and physical performance in 123 pregnant and new mothers from Somalia (n=52) and Sweden (n=71).