1.
Muscle Mass Changes After Daily Consumption of Protein Mix Supplemented With Vitamin D in Adults Over 50 Years of Age: Subgroup Analysis According to the Serum 25(OH)D Levels of a Randomized Controlled Trial.
Kang, Y, Kim, N, Lee, Y, An, X, Chung, YS, Park, YK
Clinical nutrition research. 2023;12(3):184-198
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Plain language summary
Sarcopenia is an age-related decrease in muscle mass and strength and increases the risk of falls and death. Protein intake and vitamin D are important for the maintenance of muscle mass, and the amino acid leucine plays a role in the regulation of muscle protein turnover. The aim of this 12-week double-blind, randomised, placebo-controlled trial was to evaluate the efficacy of a supplement containing protein, vitamin D, leucine and calcium for maintaining muscle mass, strength and physical functioning in healthy Koreans aged 50-80 years. Increases in muscle mass were seen in those with low vitamin D levels (< 30 ng/ml) but not in those with higher vitamin D levels. No differences were observed in muscle strength and physical functioning. The authors concluded that a supplement containing protein, including high levels of leucine, vitamin D and calcium may be of benefit for muscle mass to middle-aged and older adults with low vitamin D levels.
Expert Review
Conflicts of interest:
None
Take Home Message:
- Consider supplementing protein in combination with leucine, vitamin D and calcium in middle-aged or older adults with insufficient vitamin D levels for prevention of sarcopenia.
Evidence Category:
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X
A: Meta-analyses, position-stands, randomized-controlled trials (RCTs)
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B: Systematic reviews including RCTs of limited number
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C: Non-randomized trials, observational studies, narrative reviews
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D: Case-reports, evidence-based clinical findings
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E: Opinion piece, other
Summary Review:
Introduction
- Sarcopenia increases the risk of falls and death
- Protein and vitamin D are important for maintaining muscle mass whilst leucine is involved in regulating muscle protein turnover
- The aim of this study was to evaluate the effects of a supplement containing protein, vitamin D, leucine and calcium on muscle mass, physical functioning, muscle strength, and physical ability in middle-aged and older adults.
Methods
- Double-blind, randomised, placebo-controlled trial, with a duration of 12 weeks. Included 120 healthy Koreans aged 50-80 years
- Participants were assigned to “insufficient” subgroup if vitamin D levels were <30ng/ml and to the “sufficient” subgroup if vitamin D was 30ng/ml or higher
- Intervention: 2.5g powder (containing 20g protein (90% milk/10% soya, incl. 3g leucine), 800 IU vitamin D, 300 mg calcium) mixed into beverage of choice twice a day. Control: isocaloric placebo powder
- Primary outcome: Muscle mass determined by dual-energy X-ray absorptiometry (DXA) and bioelectrical impedance analysis (BIA)
- Secondary outcomes: Muscle strength (femoral muscle and grip strength); physical functioning (short physical performance battery (SPPB), International Physical Activity Questionnaire (IPAQ)).
Results
- At baseline, age of participants in the “sufficient” intervention subgroup was higher than that of the “sufficient” control subgroup (p=0.02)
- Increase in vitamin D levels in intervention group relative to control group, in both sufficient and insufficient subgroups (difference in changes between groups 11.5 ng/ml and 13.9 ng/ml, respectively, both p=0.00)
- No difference in change in muscle index as measured by DXA between groups
- In the “insufficient” subgroup, BIA increases in muscle mass were seen when normalised by height (p=0.037) and weight (p=0.05)
- No differences in changes in physical functioning or muscle strength between groups.
Conclusion
- The authors conclude that a supplement containing protein, with high levels of leucine, vitamin D and calcium may be of benefit for muscle mass to middle-aged and older adults with insufficient vitamin D levels.
Clinical practice applications:
- Middle-aged and older adults with insufficient vitamin D levels may gain muscle mass through supplementation of protein, leucine, vitamin D and calcium
- Middle-age and older adults with sufficient vitamin D levels do not appear to benefit from the same intervention.
Considerations for future research:
- Longer-term studies may help identify whether increases in muscle mass lead to improved physical functioning over time
- A study combining supplementation and exercise may help identify additive or synergistic effects.
Abstract
UNLABELLED Early prevention of sarcopenia can be an important strategy for muscle maintenance, but most studies target subjects at slightly pre-sarcopenic state. Our previous paper describes the effect of protein supplements rich in leucine and vitamin D on muscle condition, and in this paper, we performed a sub-analysis to evaluate who benefitted the most in terms of improvement in muscle health. A 12-week randomized clinical trial of 120 healthy adults (aged 50 to 80) assigned to an intervention group (n = 60) or control group (n = 60) were analyzed. Subjects in the intervention group received, twice per day, a protein supplement containing (per serving) 800 IU of vitamin D, 20 g of protein (3 g of total leucine), 300 mg of calcium, 1.1 g of fat, and 2.5 g of carbohydrate. The subjects were classified into 'insufficient' and 'sufficient' groups at 25-hydroxyvitamin D (25[OH]D) value of 30 ng/mL. The skeletal muscle mass index normalized to the square of the skeletal muscle mass (SMM) height (kg/m2) increased significantly in the 'insufficient group' difference value of change between weeks 0 and 12 (Δ1.07 ± 2.20; p = 0.037). The SMM normalized by body weight (kg/kg, %) was higher, but not significantly, in the insufficient group (Δ0.38 ± 0.69; p = 0.050). For people with insufficient (serum 25[OH]D), supplemental intake of protein and vitamin D, calcium, and leucine and adequate energy intake increases muscle mass in middle-aged and older adults and would be likely to exert a beneficial effect on muscle health. TRIAL REGISTRATION Clinical Research Information Service Identifier: KCT0005111.
2.
The Role of Vitamin D in Sleep Disorders of Children and Adolescents: A Systematic Review.
Prono, F, Bernardi, K, Ferri, R, Bruni, O
International journal of molecular sciences. 2022;23(3)
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Plain language summary
Vitamin D deficiency or insufficiency is a global epidemic, estimated to affect over one billion people worldwide, including children. The main function of vitamin D is the regulation of bone homeostasis but it is also involved in many other conditions such as cardiovascular disease, cancer, diabetes mellitus and autoimmune disorders. Recent studies show that sufficient levels of vitamin D seem to be necessary to maintain sleep and low vitamin D levels have been associated with shorter sleep duration. This systematic review is the first to assess the association between Vitamin D and sleep disorders in children, 14 articles were included. Vitamin D deficiency in children is associated with decreased sleep duration and poorer sleep efficiency, as well as with delayed bedtimes. Children with reduced vitamin D serum levels have a higher risk of excessive daytime sleepiness (EDS). Since vitamin D levels influence sleep duration, sleep duration can also influence vitamin D serum concentration suggesting a bidirectional relationship. Evidence is scarce and so further high-quality prospective cohort studies and well-designed randomized controlled trials (RCTs) are needed to determine the effect of vitamin D supplementation in children with sleep disorders.
Expert Review
Conflicts of interest:
None
Take Home Message:
- Vitamin D plays an important role in the sleep quality of children. Healthcare practitioners may wish to establish vitamin D status in children presenting with sleep disturbances.
Evidence Category:
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A: Meta-analyses, position-stands, randomized-controlled trials (RCTs)
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X
B: Systematic reviews including RCTs of limited number
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C: Non-randomized trials, observational studies, narrative reviews
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D: Case-reports, evidence-based clinical findings
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E: Opinion piece, other
Summary Review:
Introduction
Vitamin D levels have been associated with improved sleep in adults, but few studies have concentrated on the paediatric population. In order to identify if vitamin D plays a role regulating sleep in children and adolescents the paper reviewed studies, which looked at vitamin D in relation to sleep duration and quality of sleep. This included the following sleep disorders: obstructive sleep apnoea (OSA), restless leg syndrome (RLS) and insomnia.
Methods
- A broad systematic review following the PRISMA guidelines and using PubMed and Cochrane databases
- Search identified 748 papers. After exclusions for non-relevance, incorrect age group, or lack of data on sleep, 14 papers were included
- Due to the shortage of papers on this topic none of these papers were excluded, regardless of quality
- The participants in each study varied from 39 to 5289.
Results
The results highlighted:
- Plasma levels of vitamin D affect sleep duration and quality of sleep in children. Data taken from 5 studies
- Vitamin D cord blood levels were correlated to sleep in preschool children. Partly this was due to the mother’s vitamin D level during pregnancy affecting the level of vitamin D available to the foetus. Venous blood vitamin D level was linked to the sleep wake cycle of children. Data taken from 2 studies
- OSA was more likely to develop in children who had low vitamin D levels with a risk of 14.16% compared to a control group of 5.83% (1 study)
- Vitamin D supplementation was found to reduce neuron damage caused by hypoxia (1 study)
- An association exists between parental vitamin D insufficiency and their child’s vitamin D status (1 study). Data taken from 5 studies
- Vitamin D levels in specific diseases, such as coeliac disease (CD) showed a negative correlation with RLS
- For familial Mediterranean fever (FMF) vitamin D deficiency reduced sleep quality (36.5%). Data taken from 2 studies.
Conclusion
Notwithstanding the small number of studies, the review shows vitamin D deficiency, defined as <20 ng/mL, is associated with an increased risk for sleep disorders in children.
Clinical practice applications:
- Due to the role vitamin D plays in sleep in children, establishing vitamin D status may be useful for children presenting with sleep disturbances
- Adequate vitamin D levels during pregnancy are important to establish a vitamin D pool in the foetus
- Vitamin D supplementation is something to rule out in the case of OSA and associated hypoxia, metabolic dysfunction and systemic inflammation in children
- Due to the negative impact poor sleep has on the body, improving sleep quality at a young age could form an important part of preventative health care.
Considerations for future research:
- Additional studies are required to support the conclusion in this study
- Due to the low number of studies, any additional research should be of a high standard and include prospective cohort studies and randomised control trials.
Abstract
This review investigates the association between vitamin D and sleep disorders. Vitamin D is an essential nutrient known to play an important role in the growth and bone health of the human body, but it also appears to play a role in sleep. The goal of our review is to examine the association between vitamin D and sleep disorders in children and adolescents. We summarize the evidence about the role and the mechanism of action of vitamin D in children and adolescents with sleep disorders such as insomnia, obstructive sleep apnea (OSA), restless legs syndrome (RLS), and other sleep disorders. Systematic electronic database searches were conducted using Pubmed and Cochrane Library. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guideline was followed. The studies that met the established inclusion criteria were analyzed and compared. Results suggest a strict relationship between vitamin D deficiency in children and sleep disorders. There is evidence that vitamin D is implicated in the different neurochemical mechanisms involved in sleep regulation and mainly in the serotonergic and dopaminergic pathways. This might be responsible for the association of vitamin D deficiency and restless sleep, sleep hyperhidrosis, OSA, and RLS.