Relationship of Vitamin D Status with Muscle Mass and Muscle Strength in Young Indian Adults – Evidence from Andhra Pradesh Children and Parents Study Cohort
Bharati Kulkarni *
National Institute of Nutrition, Hyderabad, India.
Hannah Kuper
London School of Hygiene and Tropical Medicine, London, UK.
Sanjay Kinra
London School of Hygiene and Tropical Medicine, London, UK.
M Sesha Charyulu
National Institute of Nutrition, Hyderabad, India.
Yoav Ben-Shlomo
University of Bristol, Bristol, UK.
George Davey Smith
University of Bristol, Bristol, UK.
Shah Ebrahim
London School of Hygiene and Tropical Medicine, London, UK.
K.V. Radhakrishna
National Institute of Nutrition, Hyderabad, India.
*Author to whom correspondence should be addressed.
Abstract
Objectives: Positive relationship of vitamin D status with muscle mass and strength has been observed in studies from the developed countries but evidence from the developing countries is sparse. This study assessed the relationship of vitamin D status with muscle mass and muscle strength in rural young adults from Hyderabad, India.
Methods: The study participants (n=956; age 18-20 years; 42% women) were a part of Andhra Pradesh Children and Parents Study cohort which was established to assess the long term impact of early nutrition supplementation provided through a government programme. Their serum 25-hydroxyvitamin D was assessed using HPLC, appendicular skeletal muscle mass (ASM) was assessed using dual energy X-ray absorptiometry and grip strength was assessed using grip dynamometer.
Results: The participants were lean with average body mass index of 19.5 kg/m2. Prevalence of vitamin D deficiency (serum 25(OH) vitamin D3 < 20 ng/ml) was 33.6% in men and 51.4% in women. Vitamin D deficiency was associated with lower ASM (β (95% CI): - 0.38 (-0.72 to -0.05) kg; p = 0.02) with a trend of lower muscle strength in unadjusted analyses. After adjustment for relevant confounders, the relationship of vitamin D deficiency with lower ASM (β (95% CI): -0.21 (-0.37 to - 0.05) kg; p =0.01) persisted but not with lower grip strength.
Conclusions: Prevalence of vitamin D deficiency was high in these rural young adults. Vitamin D deficiency was associated with lower muscle mass but not with lower muscle strength in this cohort. Alleviation of vitamin D deficiency may improve muscle mass.