Effect of vitamin D on musculoskeletal pain and headache: A randomized, double-blind, placebo-controlled trial among adult ethnic minorities in Norway

Abstract

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 (25μg/d or 10μg/d) supplementation for 16weeks would improve musculoskeletal pain or headache compared to placebo. This randomized, double-blind, placebo-controlled, parallel-group trial recruited 251 participants aged 18 to 50years, 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 2weeks. 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 2weeks. During the past 4weeks, 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 27nmol/L to 52nmol/L and from 27nmol/L to 43nmol/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.