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Muscle increased 17 percent in vitamin D insufficient elderly getting 4,000 IU for 4 months – RCT Oct 2013

A randomized study on the effect of vitamin D3 supplementation on skeletal muscle morphology and vitamin D receptor concentration in older women

The Journal of Clinical Endocrinology & Metabolism October 9, 2013 jc.2013-2820
Lisa Ceglia 1,2,
Sathit Niramitmahapanya 2,3,
Mauricio da S. Morais 4,
Donato A. Rivas 4,
Susan S. Harris 2,
Heike Bischoff-Ferrari 2,5,6,
Roger A. Fielding 4 and
Bess Dawson-Hughes 2
1 Division of Endocrinology, Diabetes and Metabolism, Tufts Medical Center, Boston, MA;
2 Bone Metabolism Laboratory and;
4 Nutrition, Exercise Physiology and Sarcopenia Laboratory, Jean Mayer USDA Human Nutrition Research Center on Aging at Tufts University, Boston, MA;
3 Department of Medicine, Rajavithi Hospital, College of Medicine, Rangsit University, Bangkok, Thailand;
5 Centre on Aging and Mobility, University of Zurich and;
6 City Hospital Waid; Department of Geriatrics and Aging Research, University Hospital Zurich
Address all correspondence and requests for reprints to: Corresponding Author: Lisa Ceglia, MD MS, Division of Endocrinology, Diabetes, and Metabolism, Tufts Medical Center, 800 Washington Street, Box 268, Boston, MA 02111; 617–556-3085 (voice); 617–556-3305 (fax); lisa.ceglia at tufts.edu.

Context: Studies examining whether vitamin D supplementation increases muscle mass or muscle-specific vitamin D receptor (VDR) concentration are lacking.

Objective: To determine whether vitamin D3 4000 IU/d alters muscle fiber cross-sectional area (FCSA) and intramyonuclear VDR concentration over 4 months.

Design and Setting: Randomized, double-blind, placebo-controlled study in a single center.

Participants: 21 mobility-limited women (aged ≥65 years) with serum 25-hydroxyvitamin D (25OHD) levels 22.5–60 nmol/L.

Main Outcome Measures: Baseline and 4-month FCSA and intramyonuclear VDR were measured from vastus lateralis muscle cross-sections probed for muscle fiber type (I/IIa/IIx) and VDR using immunofluorescence.

Results: At baseline, mean (±SD) age was 78±5 years; body mass index (BMI) was 27±5 kg/m2; 25OHD was 46.3±9.5 nmol/L; and a short physical performance battery score was 7.95±1.57 out of 12.
At 4 months, 25OHD level was 52.5±17.1 (placebo) vs. 80.0±11.5 nmol/L (VD; P<0.01) and change in 25OHD level was strongly associated with percent change in intramyonuclear VDR concentration independent of group (r=0.87, P<0.001).
By treatment group, percent change in intramyonuclear VDR concentration was 7.8±18.2% (placebo) vs. 29.7±11.7% (VD; P=0.03) with a more pronounced group difference in type II vs. I fibers. Percent change in total (type I/II) FCSA was −7.4±18.9% (placebo) vs. 10.6±20.0% (VD; P=0.048).

Conclusion: Vitamin D3 supplementation increased intramyonuclear VDR concentration by 30% and increased muscle fiber size by 10% in older, mobility-limited, vitamin D-insufficient women. Further work is needed to determine whether the observed effect of vitamin D on fiber size is mediated by the VDR and to identify which signaling pathways are involved.

Summary by VitaminDWiki

Placebo 4,000 IU
Vitamin D 18(?) ng 32 ng
Vitamin D Receptor +8%+30%
Muscle fiber area -7%+11%

Comment by VitaminDWiki: Even more muscle increase if:

  1. Had used a restoration/loading dose - say 200,000 IU over a month
  2. Had used a higher dose of vitamin D - say 8,000 IU (Note that blood level only got to 32 ng)
  3. Trial had gone on longer than 4 months
  4. Had used some cofactors (Mg, Ca, etc.) instead of just vitamin D monotherapy; maybe also Bicarbonate - see below
  5. Had some included some exercise to encourage muscle increase - such as hydroaerobic, below

See also VitaminDWiki