Lack of significant seasonal association between serum 25(OH)D concentration, muscle mass and strength in postmenopausal women from the D-FINES longitudinal study

The aim of the present study was to assess the seasonal relationship between serum 25(OH)D concentration, lean mass and muscle strength. This was a secondary data analysis of a subgroup of 102 postmenopausal women participating in the 2006-2007 D-FINES (Vitamin D, Food Intake, Nutrition and Exposure to Sunlight in Southern England) study. The cohort was assessed as two age subgroups: <65 years (n=80) and ≥65 years (n=22). Outcome measures included lean mass (DXA), muscle strength (handgrip dynamometry) and serum 25(OH)D concentration (enzymeimmunoassay). Derived outcomes included appendicular skeletal muscle mass (ASM) and relative appendicular skeletal muscle index (RASM). Sarcopenia status was assessed using the European Working Group on Sarcopenia in Older People 2018 criteria. Non-parametric partial correlation using BMI as a covariate was used to evaluate the study aims. There were no statistically significant associations between total lean mass, ASM or RASM and 25(OH)D in any group at any season. There was a trend for handgrip strength to be positively associated with serum 25(OH)D concentration. There was a trend showing a higher prevalence of sarcopenia in women ≥65 years. Sarcopenia status appeared transient for five women. In conclusion, the present study found no significant association between vitamin D status and functional indicators of musculoskeletal health, which were additionally not affected by season.

Vitamin D3 supplementation in obese, African-American, vitamin D deficient adolescents

Objectives

Obese, African-American (AA) adolescents are at increased risk for vitamin D deficiency. The primary objective of this pilot study was to examine the effect of vitamin D supplementation upon 25-hydroxy vitamin D (25OHD) levels in obese, AA adolescents.

Methods

A randomized, double-blinded, controlled pilot study included 26 obese (BMI ≥ 95%ile), vitamin D deficient (25OHD < 20 ng/mL), pubertal AA adolescents (ages 12-17). Subjects received cholecalciferol 1000 IU or 5000 IU daily for 3 months. Serum 25OHD, vitamin D binding protein, parathyroid hormone, and cardiometabolic risk markers were obtained at baseline and post-treatment.

Results

Of 39 subjects enrolled, 26 (67%) were vitamin D deficient (mean 25OHD 12.0 ± 3.8 ng/mL) at baseline and were randomized, with 22 completing the study. Sex, age, season, pubertal stage, BMI, insulin resistance (HOMA-IR) and 25OHD were similar at baseline between the 1000 IU and 5000 IU groups. Post-treatment, 25OHD increased less in the 1000 IU group (5.6 ng/mL, p = 0.03) vs. the 5000 IU group (15.6 ng/mL, p = 0.002). 83% of the 5000 IU group and 30% of the 1000 IU group reached post-treatment 25OHD ≥ 20 ng/mL (p = 0.01); 50% of the 5000 IU group, but no subject from the 1000 IU group, achieved 25OHD ≥ 30 ng/mL (p = 0.009). We detected no group differences in mineral metabolites or cardiometabolic risk markers following supplementation.

Conclusions

Cholecalciferol dosing in excess of the current Institute of Medicine dietary reference intakes was required to achieve 25OHD levels ≥20 ng/mL in obese, AA adolescents. Supplementation of 5000 IU may be required to achieve the desired goal.

Nutrition and Muscle in Cirrhosis

As the cirrhosis progresses, development of complication like ascites, hepatic encephalopathy, variceal bleeding, kidney dysfunction, and hepatocellular carcinoma signify increasing risk of short term mortality. Malnutrition and muscle wasting (sarcopenia) is yet other complications that negatively impact survival, quality of life, and response to stressors, such as infection and surgery in patients with cirrhosis. Conventionally, these are not routinely looked for, because nutritional assessment can be a difficult especially if there is associated fluid retention and/or obesity. Patients with cirrhosis may have a combination of loss of skeletal muscle and gain of adipose tissue, culminating in the condition of "sarcopenic obesity." Sarcopenia in cirrhotic patients has been associated with increased mortality, sepsis complications, hyperammonemia, overt hepatic encephalopathy, and increased length of stay after liver transplantation. Assessment of muscles with cross-sectional imaging studies has become an attractive index of nutritional status evaluation in cirrhosis, as sarcopenia, the major component of malnutrition, is primarily responsible for the adverse clinical consequences seen in patients with liver disease. Cirrhosis is a state of accelerated starvation, with increased gluconeogenesis that requires amino acid diversion from other metabolic functions. Protein homeostasis is disturbed in cirrhosis due to several factors such as hyperammonemia, hormonal, and cytokine abnormalities, physical inactivity and direct effects of ethanol and its metabolites. New approaches to manage sarcopenia are being evolved. Branched chain amino acid supplementation, Myostatin inhibitors, and mitochondrial protective agents are currently in various stages of evaluation in preclinical studies to prevent and reverse sarcopenia, in cirrhosis.