Muscle strength not increased by raising vitamin D to only 30 ng – RCT Aug 2012

Skeletal Muscle Strength in Young Asian Indian Females after Vitamin D and Calcium Supplementation: A Double-Blind Randomized Controlled Clinical Trial

The Journal of Clinical Endocrinology & Metabolism August 17, 2012 jc.2012-2340
Ravinder Goswami, Manju Vatsa, Vishnubhatla Sreenivas, Upinderpal Singh, Nandita Gupta, Ramakrishnan Lakshmy, Sameer Aggarwal, Arthi Ganapathy, Poonam Joshi and Himani Bhatia
Departments of Endocrinology and Metabolism (R.G., N.G., S.A., A.G.), College of Nursing (M.V., P.J.), Biostatistics (V.S.), Physical Medicine and Rehabilitation (U.S., H.B.), and Cardiac Biochemistry (R.L.), All India Institute of Medical Sciences, New Delhi 110029, India
Address all correspondence and requests for reprints to: Dr. Ravinder Goswami, M.D., D.M. (Additional Professor), Department of Endocrinology and Metabolism, All India Institute of Medical Sciences, New Delhi 110029, India. E-mail: gosravinder at hotmail.com.

Context: Randomized control trials (RCT) of the effect of vitamin D/calcium supplementation on skeletal muscle strength have not shown promising effect in the elderly.

Objective: Our objective was to assess the effect of vitamin D and/or calcium on muscle strength in young adults with vitamin D deficiency.

Design and Setting: We conducted a RCT using a factorial design at a tertiary-care center from September 2010 to April 2011.

Subjects: A total of 173 healthy females with mean age, body mass index, and 25-hydroxyvitamin D [25(OH)D] of 21.7 ± 4.4 yr, 20.8 ± 2.96 kg/m2, and 9.3 ± 3.37 ng/ml, respectively, were block randomized to

• double placebo,
• calcium/placebo,
• cholecalciferol/placebo, and
• cholecalciferol/calcium for 6 months.

Cholecalciferol was given at 60,000 IU/wk for 8 wk followed by 60,000 IU/fortnight.
Elemental calcium was given in doses of 500 mg twice per day for 6 months.

Methods: Assessment included hand grip (primary outcome) and pinch grip strength, distance walked in 6 min, dyspnea score, quality of life by Short Form (36) Health Survey (SP-36), serum 25(OH)D, 1,25-dihydroxyvitamin D, and intact PTH.

Results: The serum 25(OH)D increased significantly to 29.9 ± 8.35 and 27.0 ± 9.54 ng/ml in two groups on cholecalciferol. The mean hand grip strength (19.4 ± 3.92, 21.1 ± 3.31, 20.6 ± 3.92, and 20.1 ± 4.00 kg) and its increase from baseline (0.3 ± 2.25, 0.3 ± 2.64, ?0.3 ± 2.41, and 0.6 ± 2.30 kg) were comparable in four groups at 6 months. Quality of life, urinary calcium/creatinine ratio, and adverse effects were also comparable in groups.

Conclusion: Oral cholecalciferol/calcium supplementation in the dose/schedule used is effective and safe in increasing and maintaining serum 25(OH)D.
However, this does not lead to improved skeletal muscle strength in young females.

Copyright © 2012 by The Endocrine Society
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There is controversy as to 40 ng vs 50 ng being the minimum level of vitamin D needed to increase muscle strength
The 30 ng of this study is not enough

See also VitaminDWiki

• Overview Sports and vitamin D
• More than 40 ng vitamin D for Athletes – July 2010 nice tables
• Athletes need 50 ng/ml of Vitamin D – Cannell and Hollis – 2009
• all items in the Sports and D category 263 items
• Muscle strength in youth increased with 60,000 IU vitamin D per week and 1 g Calcium – April 2010 this study used 2X as much vitamin D
• 8500 IU average daily helped sports performance – Oct 2010 this study also used about 2X as much vitamin D
• More muscle response when have adequate vitamin D another non-strength benefit of vitamin D to sports
• Shin splints decrease with vitamin D another non-strength benefit of vitamin D to sports