Vitamin D relationships and genes of a Chinese population in the Netherlands

Abstract

Vitamin D is essential for bone health. Vitamin D deficiency causes rickets and osteomalacia. In non-Western immigrants in the Netherlands, low vitamin D status is common. For example, low concentrations of 25-hydroxyvitamin D have been reported among Turkish, Moroccan, Surinamese, and sub-Saharan African populations. However, little is known about the vitamin D status of Chinese in the Netherlands. Therefore, this thesis aimed to determine the vitamin D status of a Chinese population in the Netherlands, and examined determinants of low 25-hydroxyvitamin D concentrations. Also, associations between 25-hydroxyvitamin D and bone, cardio-metabolic outcomes, and genetic factors were examined. Finally, a patient-friendly method to assess 25-hydroxyvitamin D concentration was investigated. The main result was that serum 25-hydroxyvitamin D concentration of our study population (42-46 nmol/L) appeared to be lower than that of ethnic Dutch (60-67 nmol/L), but better than other non-Western immigrant groups in the Netherlands (24-38 nmol/L), as previously found by others. Almost one-quarter of our study population, however, did not meet the requirement for an adequate vitamin D status of the Health Council of the Netherlands (Gezondheidsraad). Therefore, public health authorities and health care providers should continue to make efforts to improve the vitamin D status of non-Western immigrants.