Pakistanis living in Oslo have lower serum 1,25-dihydroxyvitamin D levels but higher serum ionized calcium levels compared with ethnic Norwegians. The Oslo Health Study

Background Persons of Pakistani origin living in Oslo have a much higher prevalence of vitamin D deficiency and secondary hyperparathyroidism but similar bone mineral density compared with ethnic Norwegians. Our objective was to investigate whether Pakistani immigrants living in Oslo have an altered vitamin D metabolism by means of compensatory higher serum levels of 1,25-dihydroxyvitamin D (s-1,25(OH)2D) compared with ethnic Norwegians; and whether serum levels of ionized calcium (s-Ca2+) differ between Pakistanis and Norwegians.Methods In a cross-sectional, population-based study venous serum samples were drawn from 94 Pakistani men and 67 Pakistani women aged 30-60 years, and 290 Norwegian men and 270 Norwegian women aged 45-60 years; in total 721 subjects.Results Pakistanis had lower s-1,25(OH)2D compared with Norwegians (p Conclusion Community-dwelling Pakistanis in Oslo with low vitamin D status and secondary hyperparathyroidism have lower s-1,25(OH)2D compared with ethnic Norwegians. However, the Pakistanis have higher s-Ca2+. The cause of the higher s-Ca2+ in Pakistanis in spite of their higher iPTH remains unclear.