Effect of increased serum 25(OH)D and calcium on structure and function of post-menopausal women: a pilot study

Abstract

Summary The purpose was to determine if increasing serum 25(OH)D and calcium in postmenopausal women increased skeletal muscle size, strength, balance, and functional task performance while decreasing muscle fatigue. PCSA of the vastus lateralis increased and ascent of stairs time decreased after 6 months of increased serum 25(OH)D. Purpose The Institute of Medicine recommends ≥ 20 ng/ml of serum 25-hydroxyvitamin D [25(OH)D] for bone and overall health. Serum 25(OH)D levels have been associated with physical performance, postural sway, and falls. The purpose of this study was to determine if increasing postmenopausal women’s serum 25(OH)D levels from 20–30 ng/ml to 40–50 ng/ml improved skeletal muscle size, strength, balance, and functional performance while decreasing skeletal muscle fatigue. Methods Twenty-six post-menopausal women (60–85 years old) with baseline serum 25(OH)D levels between 20 and 30 ng/ml were recruited. Oral over-the-counter (OTC) vitamin D3 and calcium citrate were prescribed to increase subjects’ serum 25(OH)D to levels between 40 and 50 ng/ml, serum calcium levels above 9.2 mg/dl, and PTH levels below 60 pg/ml, which were confirmed at 6 and 12 weeks. Outcome measures assessed at baseline and 6 months included muscle physiological cross-sectional area (PCSA), muscle strength, postural balance, time to perform functional tasks, and muscle fatigue. Repeated measures comparisons between baseline and follow-up were performed. Results Nineteen subjects completed the study. One individual could not afford the time commitment for the repeated measures. Three individuals did not take their vitamin D as recommended. Two subjects were lost to follow-up (lack of interest), and one did not achieve targeted serum 25(OH)D. Vastus lateralis PCSA increased (p = 0.007) and ascent of stair time decreased (p = 0.042) after 6 months of increasing serum 25(OH)D levels from 20–30 ng/ml to 40–50 ng/ml. Isometric strength was unchanged. Anterior-posterior center of pressure (COP) excursion and COP path length decreased (p < 0.1) albeit non-significantly, suggesting balance may improve from increased serum 25(OH)D and calcium citrate levels. Conclusions Several measures of muscle structure and function were sensitive to elevated serum 25(OH)D and calcium levels indicating that further investigation of this phenomenon in post-menopausal women is warranted.

Low BMI, blood calcium and vitamin D, kyphosis time, and outdoor activity time are independent risk factors for osteoporosis in postmenopausal women

“…showed that the daily intake of calcium- and vitamin D-rich milk in healthy postmenopausal women significantly improved vitamin D status, increased femoral neck BMD, and had favorable effects on glucose and lipid profiles ( 22 ). Studies have also confirmed that increased serum 25 (OH) D and calcium levels in postmenopausal women can increase skeletal muscle size, strength, balance, and functional task performance while reducing muscle fatigue ( 23 ). Furthermore, collagen peptide supplementation enhances the positive effect of calcium and vitamin D supplementation on bone metabolism in postmenopausal women ( 24 ).…”

Vitamin D status

“…al [5] studied vitamin D deficiency among north Indian athletes and considered the serum level <20 ng/ml as deficient, serum level 20-30 as insufficient, serum level >30 ng/ml as sufficient. Sinkar et.al [6] studied vitamin D deficiency picture considering 1079 Asian Indians from Indian laboratories considering clinical range <20 ng/ml as deficient, 21-30 ng/ml as insufficient, >30ng/ml as sufficient. They studied age-wise as well as gender-wise deficiency and considered the age groups 0-10, 10-25, 25-50 and age above 50.…”