Should we be concerned about the vitamin D status of athletes?
ABSTRACT A surprisingly high prevalence of vitamin D insufficiency and deficiency has recently been reported worldwide. Although very little is known about vitamin D status among athletes, a few studies suggest that poor vitamin D status is also a problem in athletic populations. It is well recognized that vitamin D is necessary for optimal bone health, but emerging evidence is finding that vitamin D deficiency increases the risk of autoimmune diseases and nonskeletal chronic diseases and can also have a profound effect on human immunity, inflammation, and muscle function (in the elderly). Thus, it is likely that compromised vitamin D status can affect an athlete's overall health and ability to train (i.e., by affecting bone health, innate immunity, and exercise-related immunity and inflammation). Although further research in this area is needed, it is important that sports nutritionists assess vitamin D (as well as calcium) intake and make appropriate recommendations that will help athletes achieve adequate vitamin D status: serum 25(OH)D of at least 75 or 80 nmol/L. These recommendations can include regular safe sun exposure (twice a week between the hours of 10 a.m. and 3 p.m. on the arms and legs for 5-30 min, depending on season, latitude, and skin pigmentation) or dietary supplementation with 1,000-2,000 IU vitamin D3 per day. Although this is significantly higher than what is currently considered the adequate intake, recent research demonstrates these levels to be safe and possibly necessary to maintain adequate 25(OH)D concentrations.
SourceAvailable from: Aleksandra Zagrodna (Kopeć)[Show abstract] [Hide abstract]
ABSTRACT: Vitamin D is synthesised in the skin during exposure to sunlight. The fundamental roles of vitamin D are the regulation of calcium and phosphate metabolism and bone mineralisation. Low vitamin D levels in athletes may adversely affect their exercise capabilities. The aim of our study was to investigate changes in serum levels of 25(OH)D3, calcium and bone turnover markers in football players in two training periods differing in the exposure to sunlight (after the summer period and after the winter period). We investigated 24 Polish professional soccer players. Serum levels of the following parameters were determined: 25(OH)D3, calcium, osteocalcin (OC), parathormone (PTH), procollagen type I N - terminal peptide (P1NP), and beta - CrossLaps (beta - CTx). We showed significantly higher levels of 25(OH)D3 and calcium and lower levels of PTH after the summer period versus the winter period. No significant differences in the levels of bone turnover markers were found. Furthermore, we did not observe any significant correlations between the levels of 25(OH)D3 and other parameters. Normal levels of 25(OH)D3 were observed in 50% of the players after the summer period and only in 16.7% of the players after the winter period. It is justified to measure the levels of 25(OH)D3, calcium and PTH in soccer players, especially after the winter period, when the exposure to sunlight is limited.Journal of Human Kinetics 09/2013; 38:135-140. DOI:10.2478/hukin-2013-0053 · 0.70 Impact Factor
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ABSTRACT: Introduction: Although vitamin D deficiency has a high worldwide prevalence among the general population, very little is known about vitamin status in athletes. Aim: To investigate serum vitamin D (25[OH]D) levels after wintertime in male elite basketball players, and to relate these levels to the dietary intake of vitamin D and calcium. Methods: Subjects were 21 players from the same professional Spanish team. Blood samples to assess 25(OH)D levels were collected after wintertime during the 2008/2009 (April) and 2009/2010 (March) seasons. In addition, athletes completed 4-day dietary records to estimate energy consumption and a food frequency questionnaire to determine dietary vitamin D and calcium intake. Serum 25(OH)D levels were 47.8 ± 21.8 nmol/L, with twelve subjects (57%) being vitamin D deficient (< 50 nmol/L). Results: Vitamin D intake was 139 ± 78 IU/day and calcium intake was 948 ± 419 mg/day. Serum 25(OH)D levels correlated with the daily dietary intake of vitamin D (r = 0.65; P = 0.001) and calcium (r = 0.82; P < 0.001). Conclusion: Professional basketball players are at higher risk of hypovitaminosis D after wintertime. Adequate intake of dietary calcium and vitamin D is required if athletes are to avoid low serum 25(OH)D levels when exposure to sunlight is limited.Nutricion hospitalaria: organo oficial de la Sociedad Espanola de Nutricion Parenteral y Enteral 10/2011; 26(5):945-951. · 1.25 Impact Factor