Our study shows a high prevalence of hypovitaminosis D in patients with non-specific musculoskeletal pain, headache, or fatigue for whom the GP had suspected a low vitamin D level. Hypovitaminosis D was not restricted to immigrant patients. These results indicate that GPs should maintain awareness of hypovitaminosis D and refer patients who report headaches, fatigue, and musculoskeletal pain with minimal sun exposure and a low dietary vitamin D intake for assessment.

Daily supplementation with 25 or 10 μg vitamin D3 for 16 weeks did not improve muscle strength or power measured by the jump test, handgrip test, or chair-rising test in this population with low baseline vitamin D status.

Immigrants from South Asia, the Middle East, and Africa living in Northern Europe frequently have low vitamin D levels and more pain compared to the native Western population. The aim of this study was to examine whether daily vitamin D3 (25 μg/d or 10 μg/d) supplementation for 16 weeks would improve musculoskeletal pain or headache compared to placebo. This randomized, double-blind, placebo-controlled, parallel-group trial recruited 251 participants aged 18 to 50 years, and 215 (86%) attended the follow-up visit. The pain measures were occurrence, anatomical localization, and degree of musculoskeletal pain, as measured by visual analogue scale (VAS) score during the past 2 weeks. Headache was measured with VAS and the Headache Impact Test (HIT-6) questionnaire. At baseline, females reported more pain sites (4.7) than males (3.4), and only 7% reported no pain in the past 2 weeks. During the past 4 weeks, 63% reported headache with a high mean HIT-6 score of 60 (SD 7). At follow-up, vitamin D level, measured as serum 25(OH)D3, increased from 27 nmol/L to 52 nmol/L and from 27 nmol/L to 43 nmol/L in the 25-μg and 10-μg supplementation groups, respectively, whereas serum 25(OH)D3 did not change in the placebo group. Pain scores and headache scores were improved at follow-up compared with baseline. The use of vitamin D supplements, however, showed no significant effect on the occurrence, anatomical localization, and degree of pain or headache compared to placebo.

BackgroundTo investigate ethnic differences in vitamin D levels during pregnancy, assess risk factors for vitamin D deficiency and explore the effect of vitamin D supplementation in women with deficiency in early pregnancy.MethodsThis is a population-based, multiethnic cohort study of pregnant women attending Child Health Clinics for antenatal care in Oslo, Norway. Serum-25-hydroxyvitamin D [25(OH)D] was measured in 748 pregnant women (59 % ethnic minorities) at gestational weeks (GW) 15 (SD:3.6) and 28 (1.4). Women with 25(OH)D <37 nmol/L at GW 15 were for ethical reasons recommended vitamin D3 supplementation. Main outcome measure was 25(OH)D, and linear regression models were performed.ResultsSevere deficiency (25(OH)D <25 nmol/L) was found at GW 15 in 45 % of women from South Asia, 40 % from the Middle East and 26 % from Sub-Saharan Africa, compared to 2.5 % in women from East Asia and 1.3 % of women from Western Europe. Women from South Asia, the Middle East and Sub-Saharan Africa had mean values that were −28 (95 % CI:-33, −23), −24 (−29, −18) and −20 (−27, −13) nmol/L lower than in Western women, respectively. Ethnicity, education, season and intake of vitamin D were independently associated with 25(OH)D. At GW 28, the mean 25(OH)D had increased from 23 (SD:7.8) to 47 (27) nmol/L (p < 0.01) in women who were recommended vitamin D supplementation, with small or no change in women with sufficient vitamin D levels at baseline.ConclusionsVitamin D deficiency was prevalent among South Asian, Middle Eastern and African women. The serum levels of 25(OH)D increased significantly from GW 15 to 28 in vitamin D deficient women who received a recommendation for supplementation. This recommendation of vitamin D supplementation increased vitamin D levels in deficient women.Electronic supplementary materialThe online version of this article (doi:10.1186/s12884-016-0796-0) contains supplementary material, which is available to authorized users.

Context:Autoimmune thyroid disorders have been linked to vitamin D deficiency, but an effect of vitamin D supplementation is not established.Objective:Our objective was to test whether vitamin D compared with placebo could reduce thyroid autoantibodies.Design:Predefined additional analyses from a randomized, double-blind, placebo-controlled trial.Setting:The study was conducted in different community centers in Oslo, Norway.Participants:A total of 251 presumed healthy men and women, aged 18 to 50 years, with backgrounds from South Asia, the Middle East, and Africa were included.Intervention:Daily supplementation with 25 µg (1000 IU) vitamin D3, 10 µg (400 IU) vitamin D3, or placebo for 16 weeks.Outcome Measure:Difference in preintervention and postintervention antithyroid peroxidase antibody (TPOAb) levels. Additional outcomes were differences in thyroid-stimulating hormone (TSH) and free fraction of thyroxine (fT4).Results:There were no differences in change after 16 weeks on TPOAb (27 kU/L; 95% CI, −17 to 72; P = 0.23), TSH (−0.10 mU/L; 95% CI, −0.54 to 0.34; P = 0.65), or fT4 (0.09 pmol/L; 95% CI, −0.37 to 0.55; P = 0.70) between those receiving vitamin D supplementation or placebo. Mean serum 25(OH)D3 increased from 26 to 49 nmol/L in the combined supplementation group, but there was no change in the placebo group.Conclusion:Vitamin D3 supplementation, 25 µg or 10 µg, for 16 weeks compared with placebo did not affect TPOAb level in this randomized, double-blind study among participants with backgrounds from South Asia, the Middle East, and Africa who had low vitamin D levels at baseline.

ObjectiveVitamin D is essential for the maintenance of calcium homeostasis and bone mineralization; and low serum 25-hydroxyvitamin D (s-25-(OH)D) concentrations are associated with increased bone turnover. However, there is a lack of randomized controlled trials that have investigated the effect of vitamin D treatment on bone turnover in immigrant populations. We aimed to investigate the effect of 16-week daily vitamin D3 supplementation on bone formation marker serum procollagen type 1 amino-terminal propeptide (P1NP) and bone resorption marker C-terminal crosslinked telopeptide of type I collagen (CTX).DesignDouble-blind, randomized, placebo-controlled trial.SettingImmigrant community centers in Oslo, Norway.Participants251 healthy adults aged 18–50 years with a non-Western immigrant background were recruited.Intervention16 weeks of daily oral supplementation with either 10 μg vitamin D3, 25 μg vitamin D3, or placebo.Main outcome measuresDifference in change during the 16-week intervention between the intervention groups combined (10 or 25 μg of vitamin D3/day) and placebo, in serum P1NP and serum CTX.ResultsA total of 214 (85%) participants completed the study. S-25-(OH)D increased from 29 nmol/L at baseline to 49 nmol/L in the intervention group with no significant change in the placebo group. However, there was no difference in change of serum P1NP (mean difference: − 1.2 μg/L (95% CI: − 5.4, 2.9, P = 0.6)) and serum CTX (mean difference: − 0.005 μg/L (95% CI: − 0.03, 0.02, P = 0.7)) between those receiving vitamin D3 supplementation compared with placebo. The plasma PTH had decreased by a mean of − 1.97 pmol/L (95% CI: − 2.7, − 1.3, P < 0.0001) in the vitamin D3 group compared to placebo.ConclusionsSupplementation with 10 or 25 μg oral vitamin D3 during winter and spring for 16 weeks did not significantly affect serum P1NP and serum CTX, despite increasing s-25(OH)D and decreasing PTH in a healthy immigrant population with low baseline vitamin D status.Trial registration number: NCT01263288.