Objectives: In the present study the diet and the nutritional status of pregnant Pakistani immigrant women have been compared with a group of Norwegian women.
Design: A cross-sectional survey of women in the 18th week of pregnancy.
Setting: Women referred to routine ultrasound examination at Aker and Ullevål Hospitals in Norway.
Subjects: All (58) healthy women of Pakistani origin referred from October of 1991 to January of 1992 were included, of whom 38 (66%) participated. Forty-five Norwegian women were randomly included in the same period and 38 (84%) of these women participated.
Results: The serum levels of 25-hydroxyvitamin D3 were significantly lower in the Pakistanis compared with the Norwegians (median 19 nmol/l vs 55 nmol/l, P < 0.001) and 83% of the Pakistani women had 25-hydroxyvitamin D3 levels below the reference value (< 30 nmol/l). The Pakistanis had higher levels of serum parathyroid hormone (median 2.6 vs 1.6 pmol/l, P < 0.001). The Pakistanis also had a lower dietary intake of vitamin D than that of the Norwegians (median 2.2 vs 3.3 micrograms/day, P < 0.05), and a lower total intake, including supplements (median 2.9 vs 7.0 micrograms/day, P < 0.001). Among the Pakistanis a correlation was found between the dietary intake of margarine, the main source of vitamin D in the diet, and the concentration of 25-hydroxyvitamin D3 in serum, r = 0.48 (P = 0.01). In general, the Pakistanis avoided any direct sunshine exposure, and no relation between outdoor activity and serum level of 25-hydroxyvitamin D3 was found. The Pakistani women had a lower intake of calcium than the Norwegians (median 793 vs 1134 mg/day, P < 0.001).
Conclusion: This study has shown that Pakistani women living in Oslo are at great risk of developing vitamin D deficiency during pregnancy. The main reasons for this are avoidance of sun exposure, a low dietary intake of vitamin D, and no or little use of supplementation.