Alcohol use disorder and muscle weakness: Original study of the effect of vitamin D supplementation in ambulatory participants with alcohol use disorder

Introduction: Chronic alcohol-related myopathy presents with proximal muscle weakness. We studied the effect of vitamin D supplementation on muscle weakness in adults with alcohol use disorder. 

Method: The study was a randomized controlled trial. Participants were community-dwelling adults with alcohol use disorder. Participants allocated to VIDIO, vitamin D intensive outreach, received bimonthly oral doses of 50,000–100,000 IU cholecalciferol for 12 months. Participants allocated to CAU, care as usual, received prescriptions of once-a-day tablets containing 800 IU cholecalciferol and 500 mg calcium carbonate. Data included demographic variables, laboratory tests, alcohol use, and rating scales of help-seeking and support. Main outcomes were the participants’ quadriceps maximum voluntary contractions (qMVC) and serum-25(OH)vitamin D concentrations, 25(OH)D. 

Results: In 66 participants, sex ratio 50/16, mean age 51 years, alcohol use was a median of 52 [IQR 24–95] drinks per week. Baseline qMVC values were 77% (SD 29%) of reference values. Laboratory tests were available in 44/66 participants: baseline 25(OH)D concentrations were 39.4 (SD 23.7) nmol/L. Thirty-one participants with 25(OH)D concentrations <50 nmol/L received either VIDIO or CAU and improved in qMVC, respectively, with a mean of 51 (p < 0.05) and 62 N (no p value because of loss of follow-up) after one year of treatment. Vitamin D status increased with a mean of +56.1 and + 37.4 nmol/L, respectively, in VIDIO and CAU. 

Conclusion: The qMVC values improved during vitamin supplementation in adults with vitamin D deficiency and alcohol use disorder. Despite higher 25(OH)D concentrations in VIDIO, in terms of muscle health no advice could be given in favor of one vitamin strategy over the other.