Vitamin D supplementation and increased dairy protein intake do not affect muscle strength or physical function in healthy 6-8-year-old children: the D-pro randomized trial.

PURPOSE: To investigate separate and combined effects of vitamin D supplementation during the extended winter and increased dairy protein intake on muscle strength and physical function in children, and furthermore to explore potential sex differences. METHODS: In a 2 × 2-factorial, randomized winter trial, 183 healthy, 6-8-year-old children received blinded tablets with 20 µg/day vitamin D3 or placebo, and substituted 260 g/day dairy with yogurts with high (HP, 10 g protein/100 g) or normal protein content (NP, 3.5 g protein/100 g) for 24 weeks during winter at 55° N. We measured maximal isometric handgrip and leg press strength, and physical function by jump tests and a 30 s sit-to-stand test. Physical activity was measured by 7-day accelerometry. RESULTS: Baseline (mean ± SD) serum 25-hydroxyvitamin D was 80.8 ± 17.2 nmol/L, which increased to 88.7 ± 17.6 nmol/L with vitamin D supplementation and decreased to 48.4 ± 19.2 nmol/L with placebo. Baseline protein intake was 15.5 ± 2.4 E%, which increased to 18.4 ± 3.4 E% with HP and was unchanged with NP. We found no separate or combined effects of vitamin D supplementation and/or increased dairy protein intake on muscle strength or physical function (all P > 0.20). There was an interaction on the sit-to-stand test (Pvitamin×yogurt = 0.02), which however disappeared after adjusting for physical activity (P = 0.16). Further, vitamin D supplementation increased leg press strength relatively more in girls compared to boys (mean [95% CI] 158 [17, 299] N; Pvitamin×sex = 0.047). CONCLUSION: Overall, vitamin D and dairy protein supplementation during the extended winter did not affect muscle strength or physical function in healthy children. Potential sex differences of vitamin D supplementation should be investigated further. REGISTERED AT CLINICALTRIALS.GOV: NCT0395673.

Effects of high dairy protein intake and vitamin D supplementation on body composition and cardiometabolic markers in 6-8-y-old children-the D-pro trial.

BACKGROUND: Increasing evidence suggests that prevention of lifestyle diseases should begin early. Dairy protein and vitamin D can affect body composition and cardiometabolic markers, yet evidence among well-nourished children is sparse. OBJECTIVES: We investigated combined and separate effects of high dairy protein intake and vitamin D on body composition and cardiometabolic markers in children. METHODS: In a 2 × 2-factorial, randomized trial, 200 white, Danish, 6-8-y-old children substituted 260 g/d dairy in their diet with high-protein (HP; 10 g protein/100 g) or normal-protein (NP; 3.5 g protein/100 g) yogurt and received blinded tablets with 20 µg/d vitamin D3 or placebo for 24 wk during winter. We measured body composition (by DXA), blood pressure, and fasting blood glucose, insulin, C-peptide, and lipids. RESULTS: In total, 184 children (92%) completed the study. Baseline median (25th-75th percentile) dairy protein intake was median: 3.7 (25th-75th percentile: 2.5-5.1) energy percentage (E%) and increased to median: 7.2 (25th-75th percentile: 4.7-8.8) E% and median: 4.2 (25th-75th percentile: 3.1-5.3) E% with HP and NP. Mean ± SD serum 25-hydroxyvitamin D concentration changed from 81 ± 17 to 89 ± 18 nmol/L and 48 ± 13 nmol/L with vitamin D and placebo, respectively. There were no combined effects of dairy protein and vitamin D, except for plasma glucose, with the largest increase in the NP-vitamin D group (Pinteraction = 0.005). There were smaller increases in fat mass index (P = 0.04) with HP than with NP, and the same pattern was seen for insulin, HOMA-IR, and C-peptide (all P = 0.06). LDL cholesterol was reduced with vitamin D compared with placebo (P < 0.05). Fat-free mass and blood pressure were unaffected. CONCLUSIONS: High compared with normal dairy protein intake hampered an increase in fat mass index. Vitamin D supplementation counteracted the winter decline in 25-hydroxyvitamin D and the increase in LDL cholesterol observed with placebo. This study adds to the sparse evidence on dairy protein in well-nourished children and supports a vitamin D intake of ∼20 µg/d during winter. This trial was registered at clinicaltrials.gov as NCT03956732.

Is Aerobic or Resistance Training the Most Effective Exercise Modality for Improving Lower Extremity Physical Function and Perceived Fatigue in People With Multiple Sclerosis? A Systematic Review and Meta-analysis.

OBJECTIVE: The purpose of this systematic review was to investigate whether aerobic training (AT) or resistance training (RT) is most effective in terms of improving lower limb physical function and perceived fatigue in persons with multiple sclerosis (PwMS). DATA SOURCES: Nine databases (MEDLINE, EMBASE, Cumulative Index to Nursing and Allied Health, Allied and Complementary Medicine Database, Physiotherapy Evidence Database, SPORTDiscus, PsycINFO, Web of Science, and Scopus) were electronically searched in April 2020. STUDY SELECTION: Included studies were randomized controlled trials (RCTs) involving PwMS attending 1 of 2 exercise interventions: AT or RT. Studies had to include at least 1 objective or self-reported outcome of lower extremity physical function and/or perceived fatigue. DATA EXTRACTION: Data were extracted using a customized spreadsheet, which included detailed information on patient characteristics, interventions, and outcomes. The methodological quality of the included studies was independently assessed by 2 reviewers using the Tool for Assessment of Study Quality for Reporting on Exercise rating scale. DATA SYNTHESIS: Twenty-seven articles reporting data from 22 RCTS (AT=14, RT=8) including 966 PwMS. The 2 modalities were found to be equally effective in terms of improving short walk test (AT: effect size [ES]=0.33 [95% confidence interval (CI), -1.49 to 2.06]; RT: ES=0.27 [95% CI, 0.07-0.47]) and long walk test performance (AT: ES=0.37 [95% CI, -0.04 to 0.78]; RT: ES=0.36 [95% CI, -0.35 to 1.08]), as well as in reducing perceived fatigue (AT: ES=-0.61 [95% CI, -1.10 to -0.11]; RT: ES=-0.41 [95% CI, -0.80 to -0.02]). Findings on other functional mobility tests along with self-reported walking performance were sparse and inconclusive. CONCLUSIONS: AT and RT appear equally highly effective in terms of improving lower extremity physical function and perceived fatigue in PwMS. Clinicians can thus use either modality to target impairments in these outcomes. In a future perspective, head-to-head exercise modality studies are warranted. Future MS exercise studies are further encouraged to adapt a consensus "core battery" of physical function tests to facilitate a detailed comparison of results across modalities.

Exercise as Medicine in Multiple Sclerosis-Time for a Paradigm Shift: Preventive, Symptomatic, and Disease-Modifying Aspects and Perspectives.

PURPOSE OF REVIEW: For many years, exercise was controversial in multiple sclerosis (MS) and thought to exacerbate symptoms and fatigue. However, having been found to be safe and effective, exercise has become a cornerstone of MS rehabilitation and may have even more fundamental benefits in MS, with the potential to change clinical practice again. The aim of this review is to summarize the existing knowledge of the effects of exercise as primary, secondary, and tertiary prevention in MS. RECENT FINDINGS: Initial studies established exercise as an effective symptomatic treatment (i.e., tertiary prevention), but recent studies have evaluated the disease-modifying effects (i.e., secondary prevention) of exercise as well as the impact on the risk of developing MS (i.e., primary prevention). Based on recent evidence, a new paradigm shift is proposed, in which exercise at an early stage should be individually prescribed and tailored as "medicine" to persons with MS, alongside conventional medical treatment.