SummaryObjective There is limited information about the prevalence of vitamin D deficiency and the effects of treatment on immigrants. The effects of oral vitamin D intake and UVB treatment on vitamin D status in healthy Somali women living in Sweden were analysed. Design Two studies were carried out; a randomized, doubleblind, placebo-controlled study, with oral drops of 800 IU and 1600 IU cholecalciferol and similar amounts of placebo given daily during 12 weeks and a single-blind, placebo-controlled study, using UVB (4Á3-8Á7 J/cm 2 ) or Woods lamp (placebo) on the upper body, or the face and hands.Patients One-hundred fourteen Somali women, mean age 34 years, latitude 0-10°N, living in Sweden >2 years, latitude 57°N, participated. Measurements Serum 25-hydroxyvitamin D (S-25(OH)D) was monitored before, every 6 weeks and at 3 months after treatment.Results The majority of the women (n = 83, 73%) were vitamin D-deficient, S-25(OH)D < 25 nmol/l at start. There was a dose-dependent increase in S-25(OH)D levels (P = 0Á001, stratified Jonckheere-Terpstra test) with a mean increase after twelve weeks in women treated with 800 IU/day and women treated with 1600 IU/day of 18 nmol/l (95% CI: 6-29, median = 17) and 29 nmol/l (95% CI: 17-42, median = 34), respectively. S-25 (OH)D decreased during follow-up but remained above baseline levels. The placebo group remained unchanged throughout the study. UVB treatment increased S-25(OH)D dose-dependently after 6 weeks (P = 0Á03, Jonckheere-Terpstra test).Conclusions Vitamin D deficiency was common in immigrants living at higher latitudes. Vitamin D treatment increased S-25 (OH)D levels dose-dependently during 3 months. The effect was maintained for another 3 months. At least 1600 IU/day is recommended. The dropout rate was high.

SummaryVitamin D deficiency can lead to osteomalacia. Bone mineral density was lower in Somali women, living in Sweden, in relation to both the American and the African–American reference populations. The majority, 73 %, had vitamin D deficiency, and supplementation should be considered to prevent from osteomalacia, osteoporosis and future fractures.PurposeLow vitamin D can lead to osteomalacia. The hypothesis was that bone mineral density (BMD) in Somali women living in Sweden was lower in comparison with different ethnic reference populations.MethodsWomen from Somalia, n = 67, median age 35.8 years (range 18 to 56), latitude 0–10° North living in Gothenburg, Sweden, latitude 57° North, >2 years were studied. All wore traditional Islamic clothing and had skin photo type V. BMD was recorded as the Z-score and compared with white American and African–American women, respectively, using standard data from the dual energy X-ray absorptiometry (DXA) manufacturer (Lunar Prodigy enCORETM, GE Healthcare, LU44663). A fasting blood test was drawn for analysis of serum 25(OH)D.ResultsThe median Z-score compared with the American white population was −0.9 SD of the lumbar spine (p < 0.00001), 0.1 SD of the left hip and 0.0 SD of the right hip (ns).The median Z-score compared with the African–American population was −1.6 SD of the lumbar spine (p < 0.00001), −0.9 SD of the left hip and −0.9 SD of the right hip (p < 0.001). The majority, 73 %, had vitamin D deficiency, serum 25(OH)D <25 nmol/l (<10 ng/ml). BMD did not correlate to vitamin D levels or to the number of years in Sweden. One wrist fracture was reported.ConclusionsBMD was lower in these fairly young immigrant women from Somalia, living in Sweden, in relation to both the American and the African–American reference populations. Vitamin D supplementation should be considered to prevent from osteomalacia, osteoporosis and future fractures.

Objective: To explore the relationship between low serum vitamin D levels and comorbidity in Somali women, immigrants to Sweden. Design and setting: Cohort study in a Primary Health Care Center and a University Hospital. Subjects: Somali women skin type V, n = 114, aged 18–56 years, from latitude 0–10 ○ N, living in Sweden, latitude 57 ○ N > 2 years were compared with women from a population sample, skin type II-III, n = 69, aged 38–56 years, the WHO MONICA study, Gothenburg, Sweden. Main outcome measures: Serum (S)-25(OH)D, S-parathyroid hormone (PTH), comorbidity and Health-Related Quality of Life (HRQoL) using the Short Form-36 (SF-36) and part of the EQ-5D questionnaires. All calculations were corrected for age. Results: Vitamin D deficiency (S-25(OH)D < 25 nmol/l) was found in 73% of the Somali women and in 1% of the controls ( p < .0001). S-PTH was elevated (>6.9 pmol/l) in 26% and 9%, respectively ( p < .004). Somali women used less medication, 16% vs. 55%, p < .0001) but more allergy medication, 11% vs. 7% ( p = .006), had fewer fractures, 2% vs. 28% ( p < .0001) and lower HRQoL in 7 out of 9 scales ( p < .05–.001), than native controls. There were no differences in the prevalence of diabetes mellitus, hypothyroidism, positive thyroid peroxidase antibodies, vitamin B12 deficiency, celiac disease or hypertension. Conclusions: Vitamin D deficiency was common in Somali women living in Sweden, 73%, but comorbidity was low. Both mental, and especially physical HRQoL scores were lower in the Somali women. The effects of long-lasting deficiency are unknown. Key points The aim was to explore the relationship between vitamin D deficiency (S-25(OH)D < 25 nmol/l) and comorbidity in immigrants. Vitamin D deficiency was common in Somali women living in Sweden, 73%, but comorbidity of hypothyroidism, diabetes mellitus, hypertension, fractures and use of medications was low. Both mental, and especially physical, Health-Related Quality of Life were lower in the Somali women than in native Swedish women. The effects of long-lasting deficiency are unknown.