DO THE EFFECTS OF VITAMIN D SUPPLEMENTATION ON MUSCLE STRENGTH DIFFER ACCORDING TO AGE?

Introduction: Vitamin D plays an important role in musculoskeletal health and its use improves muscle strength. However, the effect of vitamin D use on muscle strength in women of different ages is yet to be investigated. Therefore, in this study, we aimed to evaluate the effect of vitamin D use on muscle strength in women of different age groups and determine the differences of muscle strength gain between age groups. Materials and Method: Sixty-three women with calcidiol levels<30 ng/mL were randomly assigned and stratified by their age group as follows: Group I (aged 40-49 years), Group II (aged 50-59 years) and Group Ill (aged 60-69 years). Calcidiol levels, body mass index, fat free mass, percent fat, grip strength, arm curl, chair stand and isokinetic concentric flexor and extensor peak torque and power at 60 degrees.s-1 and 180 degrees.s-1 were assessed at baseline and six months after oral cholecalciferol supplementation. Results: Vitamin D supplementation caused significant improvement in body mass index, arm curl, grip strength and knee flexor and extensor peak torque and power at 60 degrees.s-1 and 180 degrees.s-1 in all groups (p<0.05). Knee flexor power at 60 degrees.s-1 and extensor power at 180 degrees.s-1 were significantly higher in group I than in group III (p<0.025). Conclusion: Muscle strength in response to vitamin D supplementation increased in all age groups, and isokinetic muscle power was the highest in the youngest age group studied.