Available via license: CC BY-NC 4.0
Content may be subject to copyright.
A preview of the PDF is not available
Do Young Athletes Need Vitamin D Supplement? Vitamin D Status and Deficiency Related Factor on Sports Type (Indoor vs. Outdoor), Age, Sex, Body Mass Index, Seasonal Variations in Korean Young Athletes
Figures
Figures - available via license: Creative Commons Attribution-NonCommercial 4.0 International
Content may be subject to copyright.
PURPOSE: Vitamin D plays important roles in calcium homeostasis and bone metabolism. Since vitamin D receptors (VDRs) are located in a variety of organs, including skeletal muscle, vitamin D has potentially widespread effects. The purpose of this review was to summarize the current understanding of the effects of vitamin D on muscle function and exercise performance in athletes.METHODS: In this narrative review, we summarized previous studies by searching the literature in the PubMed, Google Scholar, and Science Direct databases.RESULTS: Vitamin D has been shown to regulate multiple actions in skeletal muscle tissue, such as myocyte proliferation and growth via genomic and non-genomic molecular pathways. Higher levels of vitamin D are associated with improved skeletal muscle function and exercise performance. Moreover, in some studies, vitamin D supplementation has beneficial effects on muscle strength in athletes, especially those who are vitamin D-deficient.CONCLUSIONS: Vitamin D appears to have beneficial effects on muscle and exercise performance in athletes. However, more studies are needed to clarify the action and dosage of vitamin D in athletes.
Purpose:
The aim of this review was to discuss the effects of vitamin D on physical performance and musculoskeletal injuries in athletes and provide information on the field applications of vitamin D.
Methods:
A systematic review was conducted to identify studies on vitamin D in athletes that assessed serum vitamin D levels, vitamin D and physical performance, vitamin D and musculoskeletal injuries, and practical guidelines for supplementation of vitamin D.
Results:
Several studies reported that a high proportion of athletes had vitamin D insufficiency or deficiency. Low serum levels of vitamin D in athletes were more pronounced in winter than in other seasons, and indoor athletes had lower serum vitamin D levels than outdoor athletes. Low vitamin D levels have been demonstrated to have negative effects on muscle strength, power, and endurance; increase stress fractures and other musculoskeletal injuries; and affect acute muscle injuries and inflammation following high-intensity exercises. Therefore, periodic assessment and monitoring of vitamin D levels are necessary in athletes; the recommended serum level of 25(OH)D is > 32 ng/mL and the preferred level is > 40 ng/mL (-1). In those with low levels of vitamin D, exposure to sunlight and an improved diet or supplements may be helpful. Particularly, 2000-6000 IU of supplemental vitamin D3 can be consumed daily.
Conclusion:
Vitamin D is a potential nutritional factor that can significantly affect physical performance and musculoskeletal injuries in athletes. The importance and role of vitamin D in athletes should be emphasized, and the current levels of vitamin D should be assessed. Therefore, it is essential to periodically evaluate and monitor serum vitamin D levels in athletes.
Abstract Background Abnormalities in the clinical markers of metabolic syndrome (MS) are associated with the development of cardiovascular disease, type 2 diabetes mellitus, and some cancers. MS prevalence in Korea increased between the mid-1990s and mid-2000s; however, no data on the recent trends of MS prevalence are available. Thus, we aimed to investigate the prevalence of MS, the five components of MS, and the related risk factors in Korean adults by using recent data. Methods Data from the Korean National Health and Nutrition Examination Survey conducted between 2008 and 2013 were used. The revised National Cholesterol Education Program criteria were used for defining MS. A multivariate logistic regression analyses was used to estimate the relationship between the related risk factors including behaviors, dietary factors, and the prevalence of MS. Results A total of 34,587 men and women were included in the analysis. Age-adjusted prevalence of MS in 2013 was 28.9% without a significant increasing or decreasing trend between 2008 and 2013. Among the five components of MS, abdominal obesity decreased in both men and women (annual percent change: −2.0 and −2.5%, respectively), the decrease being significant only in women, whereas blood pressure and blood glucose significantly increased in men (+1.9 and +2.7%, respectively). Age and obesity (odds ratio = 6.7, 95% confidence interval = 5.9–7.5 for body mass index ≥25 kg/m2 vs. body mass index
Background:
Vitamin D plays an important role in several systems of the human body. Various studies have linked vitamin D deficiency to stress and insufficiency fractures, muscle recovery and function, and athletic performance. The prevalence of vitamin D deficiency in the elite athletic population has not been extensively studied, and very few reports exist among professional athletes.
Hypothesis:
There is a high prevalence of vitamin D deficiency or insufficiency among players attending the National Basketball Association (NBA) Combine.
Study design:
Cross-sectional study; Level of evidence, 3.
Methods:
This is a retrospective review of data previously collected as part of the routine medical evaluation of players in the NBA Combines from 2009 through 2013. Player parameters evaluated were height, weight, body mass index (BMI), and vitamin D level. Statistical analysis using t tests and analysis of variance was used to detect any correlation between the player parameters and vitamin D level. Vitamin D levels were categorized as deficient (<20 ng/mL), insufficient (20-32 ng/mL), and sufficient (>32 ng/mL).
Results:
After institutional review board approval was submitted to the NBA, the NBA released deidentified data on 279 players who participated in the combines from 2009 through 2013. There were 90 players (32.3%) who were deficient, 131 players (47.0%) who were insufficient, and 58 players (20.8%) who were sufficient. A total of 221 players (79.3%) were either vitamin D deficient or insufficient. Among all players included, the average vitamin D level was 25.6 ± 10.2 ng/mL. Among the players who were deficient, insufficient, and sufficient, the average vitamin D levels were 16.1 ± 2.1 ng/mL, 25.0 ± 3.4 ng/mL, and 41.6 ± 8.6 ng/mL, respectively. Player height and weight were significantly increased in vitamin D-sufficient players compared with players who were not sufficient (P = .0008 and .009, respectively). Player age and BMI did not significantly differ depending on vitamin D status (P = .15 and .77, respectively).
Conclusion:
There is a high prevalence of vitamin D deficiency or insufficiency among participants in the NBA Combines. As a result, there should be a high suspicion for this metabolic abnormality among elite basketball players.
Clinical relevance:
Vitamin D level has been linked to bone health, muscle recovery and function, and athletic performance. Because of the high prevalence of vitamin D deficiency in the NBA Combines, clinicians should maintain a high suspicion for vitamin D abnormalities among elite basketball players.
Vitamin D is well known for its role in calcium regulation and bone health, but emerging literature tells of vitamin D's central role in other vital body processes, such as: signaling gene response, protein synthesis, hormone synthesis, immune response, plus, cell turnover and regeneration. The discovery of the vitamin D receptor within the muscle suggested a significant role for vitamin D in muscle tissue function. This discovery led researchers to question the impact that vitamin D deficiency could have on athletic performance and injury. With over 77% of the general population considered vitamin D insufficient, it's likely that many athletes fall into the same category. Research has suggested vitamin D to have a significant effect on muscle weakness, pain, balance, and fractures in the aging population; still, the athletic population is yet to be fully examined. There are few studies to date that have examined the relationship between vitamin D status and performance, therefore, this review will focus on the bodily roles of vitamin D, recommended 25(OH)D levels, vitamin D intake guidelines and risk factors for vitamin D insufficiency in athletes. In addition, the preliminary findings regarding vitamin D's impact on athletic performance will be examined.
Obesity is a significant health problem world-wide, particularly in developed nations. Vitamin D deficiency is pandemic, and has been implicated in a wide variety of disease states. This paper seeks to examine the consistently reported relationship between obesity and low vitamin D concentrations, with reference to the possible underlying mechanisms. The possibility that vitamin D may assist in preventing or treating obesity is also examined, and recommendations for future research are made. There is a clear need for adequately-powered, prospective interventions which include baseline measurement of 25D concentrations and involve adequate doses of supplemental vitamin D. Until such studies have been reported, the role of vitamin D supplementation in obesity prevention remains uncertain.
Abstract The current study implemented a two-part design to (1) assess the vitamin D concentration of a large cohort of non-vitamin D supplemented UK-based athletes and 30 age-matched healthy non-athletes and (2) to examine the effects of 5000 IU · day(-1) vitamin D(3) supplementation for 8-weeks on musculoskeletal performance in a placebo controlled trial. Vitamin D concentration was determined as severely deficient if serum 25(OH)D < 12.5 nmol · l(-1), deficient 12.5-30 nmol · l(-1) and inadequate 30-50 nmol · l(-1). We demonstrate that 62% of the athletes (38/61) and 73% of the controls (22/30) exhibited serum total 25(OH)D < 50 nmol · l(-1). Additionally, vitamin D supplementation increased serum total 25(OH)D from baseline (mean ± SD = 29 ± 25 to 103 ± 25 nmol · l(-1), P = 0.0028), whereas the placebo showed no significant change (53 ± 29 to 74 ± 24 nmol · l(-1), P = 0.12). There was a significant increase in 10 m sprint times (P = 0.008) and vertical-jump (P = 0.008) in the vitamin D group whereas the placebo showed no change (P = 0.587 and P = 0.204 respectively). The current data supports previous findings that athletes living at Northerly latitudes (UK = 53° N) exhibit inadequate vitamin D concentrations (<50 nmol · l(-1)). Additionally the data suggests that inadequate vitamin D concentration is detrimental to musculoskeletal performance in athletes. Future studies using larger athletic groups are now warranted.
Background: Obesity is associated with vitamin D insufficiency and secondary hyperparathyroidism.
Objective: This study assessed whether obesity alters the cutaneous production of vitamin D3 (cholecalciferol) or the intestinal absorption of vitamin D2 (ergocalciferol).
Design: Healthy, white, obese [body mass index (BMI; in kg/m²) ≥ 30] and matched lean control subjects (BMI ≤ 25) received either whole-body ultraviolet radiation or a pharmacologic dose of vitamin D2 orally.
Results: Obese subjects had significantly lower basal 25-hydroxyvitamin D concentrations and higher parathyroid hormone concentrations than did age-matched control subjects. Evaluation of blood vitamin D3 concentrations 24 h after whole-body irradiation showed that the incremental increase in vitamin D3 was 57% lower in obese than in nonobese subjects. The content of the vitamin D3 precursor 7-dehydrocholesterol in the skin of obese and nonobese subjects did not differ significantly between groups nor did its conversion to previtamin D3 after irradiation in vitro. The obese and nonobese subjects received an oral dose of 50000 IU (1.25 mg) vitamin D2. BMI was inversely correlated with serum vitamin D3 concentrations after irradiation (r = −0.55, P = 0.003) and with peak serum vitamin D2 concentrations after vitamin D2 intake (r = −0.56, P = 0.007).
Conclusions: Obesity-associated vitamin D insufficiency is likely due to the decreased bioavailability of vitamin D3 from cutaneous and dietary sources because of its deposition in body fat compartments.
By maintaining phosphate and calcium homeostasis, vitamin D is critical for bone health and possibly physical performance. Hence, vitamin D is important to athletes. Few studies have investigated vitamin D levels in relation to fractures and performance in athletes, and no published study has included a multiracial sample of professional American football players.
To assess vitamin D levels, including the prevalence of vitamin D deficiency/insufficiency, in professional American football players and to evaluate the association of vitamin D levels with race, fracture history, and the ability to obtain a contract position, which may be a marker for athletic performance.
Cohort study; Level of evidence, 3.
Serum vitamin D levels of 80 professional football players from a single team in the National Football League were obtained during the 2011 off-season (mean age, 26.5 ± 3.7 years; black, n = 67 [84%]). These levels were used to compare injury reports from the 2011-2012 and 2012-2013 seasons. Statistical analyses were performed to test if vitamin D levels were related to race, fracture history, and the ability to obtain a contract position.
Mean vitamin D level was 27.4 ± 11.7 ng/mL, with significantly lower levels for black players (25.6 ± 11.3 ng/mL) versus white players (37.4 ± 8.6 ng/mL; F 1,78 = 13.00, P = .001). All athletes who were vitamin D deficient were black. When controlling for number of professional years played, vitamin D levels were significantly lower in players with at least 1 bone fracture when compared with no fractures. Players who were released during the preseason because of either injury or poor performance had significantly lower vitamin D levels than did players who played in the regular season.
Black professional football players have a higher rate of vitamin D deficiency than do white players. Furthermore, professional football players with higher vitamin D levels were more likely to obtain a contract position in the National Football League. Professional football players deficient in vitamin D levels may be at greater risk of bone fractures.
© 2015 The Author(s).
Age-related changes affect vitamin D metabolism and increase the requirement for vitamin D in the elderly. Also there is an age related decrease in calcium absorption and a higher calcium intake is needed. Increasing calcium from dietary sources may be better than supplements, and requires increasing the intake of dairy products or other and calcium-fortified foods. Evidence suggests that vitamin D and calcium nutrition can be improved in the elderly by increasing the vitamin D intake to 800 IU daily together with a total calcium intake of 1000 mg daily. This combination is a simple, inexpensive strategy that can reduce fractures in institutionalized individuals by 30%.