Vitamin-D-Mangel im Sport
Abstract
Zusammenfassung. Ein Mangel an Vitamin D ist in der allgemeinen Bevölkerung wie auch bei Sportlerinnen und Sportlern sehr häufig. Ziel dieser Übersicht ist, den Stand des Wissens um die Bedeutung von Vitamin D für den sportlich aktiven Menschen zusammenzustellen. Ein Vitamin-D-Mangel liegt bei Sportlerinnen und Sportlern in bis zu 90 % vor. Risikogruppen bzw. -faktoren sind junge Sportler/innen, weibliches Geschlecht, Sportler/innen mit einer Einschränkung wie z.B. Querschnittgelähmte, Vegetarier/innen, Sportler/innen mit einer Resorptionsstörung wie Zöliakie, diejenigen, die in Hallen trainieren und dort auch Wettkämpfe durchführen (Eishockey, Basketball, Boxen, Rhythmische Sportgymnastik), ältere Sportler/innen, dunkle Hautpigmentation, der Gebrauch von Sonnenschutz, die Tageszeit des Trainings (früher Morgen, später Abend) sowie die geografische Lage. Sonnenexposition sowie eine ausgewogene Ernährung reichen oft nicht aus, um einen Vitamin-D-Mangel zu verhindern.
Abstract. A deficiency in vitamin D is very common in the general population as well as in athletes. The aim of this overview is to assess the level of knowledge about the importance of vitamin D for athletes. A deficiency in vitamin D is present in up to 90 % of athletes. Risk groups are young athletes, female athletes, athletes with a limitation such as paraplegia, vegetarians, athletes with a resorption disorder such as celiac disease, athletes training and competing indoors (e.g. ice hockey, basketball, boxing, rhythmic gymnastics), and older athletes. Dark skin pigmentation, the use of sunscreen, the time of day of the training (early morning, late evening) and the geographical location influence the risk for a deficiency in vitamin D. Exposure to the sun and a balanced diet are often not enough to prevent a vitamin D deficiency.
Résumé. Une carence en vitamine D est très courante dans la population générale comme aussi chez les sportifs. Le but de cet aperçu est de compiler l’état des connaissances sur l’importance de la vitamine D pour les athlètes. Jusqu’à 90 % des athlètes présentent une carence en vitamine D. Chez les athlètes, les groupes à risque et les situations à risque sont: les jeunes athlètes, les athlètes de sexe féminin, les sportifs ayant une déficience tels que les paraplégiques, les végétariens, les athlètes présentant un trouble de la résorption tel que la maladie cœliaque, les athlètes s’entraînant et participant à une compétion en salle (hockey sur glace, basket-ball, boxe, gymnastique rythmique), les athlètes plus âgés, ceux qui ont une peau foncée et ceux qui utilisent un écran solaire. L’heure de la journée d’entraînement (tôt le matin, tard le soir) et la situation géographique entrent aussi en jeu dans la déficience en vitamine D. L’exposition au soleil et une alimentation équilibrée ne suffisent souvent pas à prévenir une carence en vitamine D.
Bibliografie
, Evaluation, treatment, and prevention of vitamin D deficiency: an Endocrine Society clinical practice guideline. J Clin Endocrinol Metab. 2011;96(7):1911–1930.
. Deficiency of sunlight and vitamin D. BMJ (Clin Res ed). 2008;336(7657):1318–1319.
. Vitamin D deficiency. N Engl J Med. 2007;357(3):266–281.
. The prevalence and risk factors of vitamin D inadequacy among male athletes in Kuwait: A cross-sectional study. J Steroid Biochem Mol Biol. 2019;187:76–81.
. Vitamin D insufficiency, deficiency, and bone health. J Clin Endocrinol Metab. 2010; 95(6):2630–2633.
. Vitamin D status in the elderly: seasonal substrate deficiency causes 1,25–dihydroxycholecalciferol deficiency. Am J Clin Nutr. 1987;45(4):755–763.
. Vitamin D metabolites and calcium absorption in severe vitamin D deficiency. J Bone Miner Res. 2008; 23(11):1859–1863.
Prevention and management of osteoporosis. World Health Organization technical report series. 2003;921:1–164.
, Hypovitaminosis D myopathy without biochemical signs of osteomalacic bone involvement. Calcif Tissue Int. 2000; 66(6):419–424.
. Effect of Vitamin D on skeletal muscle. Geriatr Psychol Neuropsychiatr Vieil. 2016; 14(2):127–134.
. Muscle performance and enzymatic adaptations to sprint interval training. J Appl Physiol ( 1985 ). 1998; 84(6):2138–2142.
, Prevalence of vitamin D inadequacy in athletes: A systematic review and meta-analysis. Sports Med. 2015;45(3):365–378.
. Prevalence of vitamin D insufficiency in Canada and the United States: importance to health status and efficacy of current food fortification and dietary supplement use. Nutr Rev. 2003;61(3):107–113.
. Vitamin D: a critical and essential micronutrient for human health. Front Physiol. 2014;5:248.
. Vitamin D metabolism, mechanism of action, and clinical applications. Chem Biol. 2014;21(3):319–329.
. Vitamin D for health: a global perspective. Mayo Clin Proc. 2013; 88(7):720–755.
. Vitamin D and neurocognitive function. Clin Interv Aging. 2014;9:559–568.
. Vitamin D and the athlete: current perspectives and new challenges. Sports Med. 2018; 48(Suppl 1): 3–16.
. Vitamin D and muscle trophicity. Curr Opin Clin Nutr Metab Care. 2017; 20(3):169–174.
. Vitamin D supplementation reduces the symptoms of upper respiratory tract infection during winter training in vitamin D-insufficient taekwondo athletes: A randomized controlled trial. Int J Environ Res Public Health. 2018;15(9):2003.
. Tibial bone responses to 6-month calcium and vitamin D supplementation in young male jockeys: A randomised controlled trial. Bone. 2015;81:554–561.
. Competitive athletic participation, thigh muscle strength, and bone density in elite senior athletes and controls. J Strength Cond Res. 2013;27(11):3132–3141.
, Influence of developmental and hormonal factors on bone health in adolescent females: A cross-sectional study and review of the literature. J Pediatr Endocrinol Metab. 2013;26(3–4):239–246.
. Beneficial effects of UV radiation other than via vitamin D production. Dermatoendocrinol. 2012;4(2):109–117.
. Is there an optimal vitamin D status for immunity in athletes and military personnel? Exerc Immunol Rev. 2016;22:42–64.
. Dietary supplements for health, adaptation, and recovery in athletes. Int J Sport Nutr Exerc Metab. 2018;28(2):188–199.
. Making decisions about supplement use. Int J Sport Nutr Exerc Metab. 2018;28(2):212–219.
, Selected in-season nutritional strategies to enhance recovery for team sport athletes: A practical overview. Sports Med. 2017;47(11):2201–2218.
. Vitamin D and sports. J Trauma Sport. 2016;33(2):110–113.
. Vitamin D and athletic performance: The potential role of muscle. Asian J Sports Med. 2011;2(4):211–219.
. Athletic performance and vitamin D. Med Sci Sports Exerc. 2009;41(5):1102–1110.
. Sunlight «D»ilemma: risk of skin cancer or bone disease and muscle weakness. Lancet. 2001;357(9249):4–6.
, Sunlight, tanning booths, and vitamin D. J Am Acad Dermatol. 2005;52(5):868–876.
. The vitamin D questions: how much do you need and how should you get it? J Am Acad Dermatol. 2006;54(2):301–317.
. Vitamin D in health and disease. Clin J Am Soc Nephrol. 2008;3(5):1535–1541.
. Evaluation of solar exposure, intake and physical activity in relation with vitamin D serum status in Spanish prepubertal girls. Nutr Hosp. 2012;27(6):1993–1998.
. Contribution of sun exposure to the vitamin D dose received by various groups of the Spanish population. Sci Total Environ. 2018;619–620:545–551.
. High prevalence of vitamin d insufficiency among elite spanish athletes; the importance of outdoor training adaptation. Nutr Hosp. 2014;30(1):124–31.
. Comparison of the somatotype, nutritional assessment and food intake among university sport and sedentary students. Med Clin (Barc). 2012;139(2):54–60.
. Dietary intake of a physically active elderly Spanish male group of high socioeconomic status. Int J Food Sci Nutr. 1996;47(4):307–313.
. Nutritional adequacy of different menu settings in elite Spanish adolescent soccer players. Int J Sport Nutr Exerc Metab. 2007;17(5):421–32.
. Intake of antioxidant vitamins and minerals by young cyclists, comparison with their homologous Spanish population. Rev Espanola Nutr Comunitaria. 2006;12(2):83–92.
. Vitamin D inadequacy is widespread in Tunisian active boys and is related to diet but not to adiposity or insulin resistance. Libyan J Med. 2016;11.
, Vitamin D status and determinants of deficiency in non-supplemented athletes during the winter months in Tunisia. Biol Sport. 2015;32(4):281–287.
. Vitamin D deficiency is endemic in Middle Eastern sportsmen. Public Health Nutr. 2010;13(10):1528–1534.
. Vitamin D in relation to bone health and muscle function in young female soccer players. Eur J Sport Sci. 2017;17(2):249–2456.
, Characterization of skeletal parameters in a cohort of North Italian rugby players. J Endocrinol Invest. 2014;37(7):609–617.
, Vitamin D status and supplementation in elite Irish athletes. Int J Sport Nutr Exerc Metab. 2013;23(5):441–448.
. Seasonal variation in vitamin D status in professional soccer players of the English premier league. Appl Physiol Nutr Metab. 2012;37(4):798–802.
. Vitamin D insufficiency in adolescent males in Southern Tasmania: Prevalence, determinants, and relationship to bone turnover markers. Osteoporos Int. 2005; 16(6):636–641.
. Low levels of vitamin D in professional basketball players after wintertime: relationship with dietary intake of vitamin D and calcium. Nutr Hosp. 2011;26(5):945–951.
, Vitamin D status and musculoskeletal health in adolescent male ballet dancers a pilot study. J Dance Med Sci. 2011;15(3):99–107.
. Serum 25–hydroxyvitamin D in early autumn to ensure vitamin D sufficiency in mid-winter in professional football players. Clin Nutr. 2012;31(1):132–136.
, Rates of insufficiency and deficiency of vitamin D levels in elite professional male and female skiers: A chronobiologic approach. Chronobiol Int. 2018;35(4):441–419.
, Seasonal variation in Vitamin D status in elite athletes: A longitudinal study. Int J Sport Nutr Exerc Metab. 2017;27(1):6–10.
. Location and vitamin D synthesis: is the hypothesis validated by geophysical data? J Photochem Photobiol B. 2007;86(3):234–239.
. Serum Vitamin D Depends Less on Latitude Than on Skin Color and Dietary Intake During Early Winter in Northern Europe. J Pediatr Gastroenterol Nutr. 2016;62(4):643–649.
, Vitamin D intake is low and hypovitaminosis D common in healthy 9– to 15-year-old Finnish girls. Eur J Clin Nutr. 1999;53(9):746–751.
. 25(OH)D levels in trained versus sedentary university students at 64 degrees north. Int J Circumpolar Health. 2017;76(1):1314414.
, Assessment of vitamin D concentration in non-supplemented professional athletes and healthy adults during the winter months in the UK: Implications for skeletal muscle function. J Sports Sci. 2013;31(4):344–353.
. Seasonal Vitamin D status in polish elite athletes in relation to sun exposure and oral supplementation. PLoS ONE. 2016;11(10).
. Vitamin D status relative to diet, lifestyle, injury, and illness in college athletes. Med Sci Sports Exerc. 2011;43(2):335–343.
. Seasonal variations in vitamin D status in indoor and outdoor female athletes. Biomedical Rep. 2016;5(1): 13–117.
. Who, what, where and when-influences on cutaneous vitamin D synthesis. Prog Biophys Mol Biol. 2006;92(1):17–25.
, Global vitamin D status and determinants of hypovitaminosis D. Osteoporos Int. 2009; 20(11):1807–1820.
, Knowledge and attitudes to vitamin D and sun exposure in elite New Zealand athletes: a cross-sectional study. J Int Soc Sports Nutr. 2014;11(1):47.
. Use of topical sunscreen for the evaluation of regional synthesis of vitamin D3. J Am Acad Dermatol. 1990;22(5 Pt 1):772–775.
. Vitamin D and muscle function. Osteoporos Int. 2002; 13(3):187–194.
, Prevalence of Abnormal Vitamin D Levels Among Division I NCAA Athletes. Sports Health. 2014;6(4):340–347.
. Vitamin D and athletes. Curr Sports Med Rep. 2010;9(4):220–226.
. Measurements of the upper body ultraviolet exposure to golfers: Non-melanoma skin cancer risk, and the potential benefits of exposure to sunlight. Photodermatol Photoimmunol Photomed. 2009; 25(6):317–324.
. Vitamin D deficiency in Swiss elite wheelchair athletes. Spinal Cord. 2016;54(11):991–995.
, Predictive factors for vitamin D concentrations in Swiss athletes: A cross-sectional study. Int J Sports Med. 2018;2(5):E148–e56.
, Photoprotection, solar exposure, and vitamin D in active and sedentary eutrophic adolescents. J Exerc Physiol Online. 2017;20(4):76–87.
. Nutrition status of young elite female German football players. Pediatr Exerc Sci. 2018;30(1):159–169.
. Nutritional intake and body composition changes in a UCI World Tour cycling team during the Tour of Spain. Eur J Sport Sci. 2019;19(1):86–94.
, Characterization and comparison of nutritional intake between preparatory and competitive phase of highly trained athletes. Medicina (Lithuania). 2018;54(3).
. An evaluation of diets in the Polish national judo team during the pre-competition weight loss period. Archiv Budo. 2017;13:101–106.
. Telehealth coaching: Impact on dietary and physical activity contributions to bone health during a military deployment. Military Med. 2016;181(5):191–198.
. Energy and nutrient issues in athletes with spinal cord injury: Are they at risk for low energy availability? Nutrients. 2018;10(8).
. Nutritional aspects of the female athlete. Clin Sports Med. 2017;36(4):627–653.
, Pre-season dietary intake of professional soccer players. Nutr Health. 2017;23(4):215–222.
, Basic principles of sports nutrition. Curr Nutr Rep. 2016;5(3):213–222.
. The female athlete triad: Special considerations for adolescent female athletes. Transl Pediatr. 2017;6(3):144–149.
. Nutritional recommendations and guidelines for women in gymnastics: Current aspects and critical interventions. Science Gymnastics J. 2017;9(1):27–40.
. Poor precompetitive sleep habits, nutrients’ deficiencies, inappropriate body composition and athletic performance in elite gymnasts. Eur J Sport Sci. 2016;16(6):726–735.
, Blood essential trace elements and vitamins in students with different physical activity. Pakistan J Nutr. 2015;14(10):721–726.
. Low energy availability and low body fat of female gymnasts before an international competition. Eur J Sport Sci. 2015;15(7):591–599.
. Evaluation of dietary intake of vitamins and minerals in 13–15-years-old boys from a sport school in Warsaw. Rocz Panstw Zakl Hig.. 2016;67(1):59–68.
. Nutritional recommendations for synchronized swimming. Int J Sport Nutr Exerc Metab. 2014;24(4):404–413.
. Nutrition status of junior elite canadian female soccer athletes. Int J Sport Nutr Exerc Metab. 2011;21(6):507–514.
. Comparison of nutritional intake between volleyball and basketball women athletes of the olympic national teams. Gazz Med Ital. 2008;167(4):147–152.
. Food preferences, dieting behaviors, and body image perceptions of elite figure skaters. Int J Sport Nutr Exerc Metab. 2004;14(5):594–606.
. Dietary intake of female U.S. soccer players. Nutr Res. 2003;23(5):585–593.
. Influence of dietetic and anthropometric factors and of the type of sport practised on bone density in different groups of women. Eur J Clin Nutr. 2003;57:S58–S62.
. Low energy availability assessed by a sport-specific questionnaire and clinical interview indicative of bone health, endocrine profile and cycling performance in competitive male cyclists. BMJ Open Sport Exerc Med. 2018;4(1).
. Prevention of rib stress injury in rowers. What do we know and where do we need to go? Orthop Traumatol Surg Res. 2018; 34(3):278–286.
, Self-administration of medicines and dietary supplements among female amateur runners: A cross-sectional analysis. Adv Ther. 2017; 33(12):2257–2268.
. Nutritional supplements use in high-performance athletes is related with lower nutritional inadequacy from food. J Sport Health Sci. 2016;5(3):368–374.
. Nutrition and nutritional issues for dancers. Med Probl Perform Art. 2013; 28(3):119–123.
. Dietary intakes and supplement use in pre-adolescent and adolescent Canadian athletes. Nutrients. 2016;8(9).
. Proposal of a nutritional quality index (NQI) to evaluate the nutritional supplementation of sportspeople. PLoS ONE. 2015;10(5).
. American College of Sports Medicine position stand. Nutrition and athletic performance. Med Sci Sports Exerc. 2009; 41(3):709–731.
. Clinical importance of extra vitamins from supplements and enriched foodstuffs. Ned Tijdschr Geneeskd. 1999; 143(17):889–893.
. Use of vitamin supplements in children during convalescence and in children performing sports. Minerva Pediatr. 1999;51(1–2):1–9.
. Association of Serum 25-Hydroxyvitamin D Concentrations With Glucose Profiles in Male Collegiate Football Athletes. Int J Sport Nutr Exerc Metab. 2019:1–6.
, Prevalence of vitamin D deficiency amongst soccer athletes and effects of 8 weeks supplementation. J Sports Med Phys Fitness. 2019;59(4):693–699.
. High prevalence of vitamin D insufficiency in professional handball athletes. Phys Sportsmed. 2019;47(1):71–77.
. Prevalence of Vitamin D onsufficiency in professional hockey players. Orthop J Sports Med. 2016;4(12).
. Vitamin D and weight cycling: Impact on injury, illness, and inflammation in collegiate wrestlers. Nutrients. 2016;8(12).
. Vitamin D and the athlete: Risks, recommendations, and benefits. Nutrients. 2013;5(6):1856–1868.
. Vitamin D and skeletal muscle function in athletes. Curr Opin Clin Nutr Metab Care. 2014;17(6):539–545.
. Vitamin D and the athlete: Emerging insights. Eur J Sport Sci. 2015;15(1):73–84.
. Vitamin D status of females in an elite gymnastics program. Clin J Sport Med. 2008;18(2):159–161.
. The association between iron and vitamin D status in female elite athletes. Nutrients. 2018;10(2).
. Evaluation of dietary intakes and supplement use in paralympic athletes. Nutrients. 2017;9(11).
. Key nutritional strategies to optimize performance in para athletes. Phys Med Rehabil Clin N Am. 2018;29(2):283–298.
. 25(OH)D status of elite athletes with spinal cord injury relative to lifestyle factors.
. Risk of nutrient inadequacies in elite canadian athletes with spinal cord injury. Int J Sport Nutr Exerc Metab. 2011;21(5):417–425.
. Nutritional Considerations for the Vegetarian and Vegan Dancer. Psychological Risk Factors and Outcomes of Dance Injury: A Systematic Review. . J Dance Med Sci. 2018;22(1):44–53.
. Vegetarian diet and athletes. Int SportMed J. 2009;10(1).
. Vegetarian diets: Nutritional considerations for athletes. Sports Med. 2006;36(4):293–305.
. Celiac disease and the athlete. Curr Sports Med Rep. 2011;10(2):105–108.
. High prevalence of vitamin D insufficiency in athletes and dancers. Clin J Sport Med. 2010;20(5):368–371.
. Nutrition for special populations: young, female, and masters athletes. Int J Sport Nutr Exerc Metab. 2019;29(2):220–227.
. Evaluation of dietary intakes, body composition, and cardiometabolic parameters in adolescent team sports elite athletes: A cross-sectional study. Adv Biomed Res. 2017;6:107.
. Determinants of plasma 25-hydroxyvitamin D levels in healthy adults in the Netherlands. Neth J Med. 2014;72(10):533–540.
. Treatment strategies for the female athlete triad in the adolescent athlete: current perspectives. Open Access J Sports Med. 2017;8:85–95.
. Comparison of strategies for assessing nutritional adequacy in elite female athletes’ dietary intake. Int J Sport Nutr Exerc Metab. 2010;20(3):245–256.
. Vitamin D level in employees of a swiss university geriatric hospital. Praxis. 2018;107(12):633–640.
. Determinants of vitamin D status in healthy men and women aged 40–80 years. Maturitas. 2013;74(1):79–83.
, Vitamin D status and muscle function among adolescent and young swimmers. Int J Sport Nutr Exerc Metab. 2017;27(5):399–407.
, Vitamin D deficiency in young women population: An unrecognised reality. Cah Nutrit Dietetique. 2009;44(6):264–272.
. Risk factors for vitamin D deficiency in women aged 2050 years consulting in general practice: A cross–sectional study. Eur J Gen Pract. 2011;17(3):146–152.
. Vitamin D insufficiency among professional basketball players: A relationship to fracture risk and athletic performance. Orthop J Sports Med. 2018;6(5): 2325967118774329.
. Vitamin D status and its relation to exercise performance and iron status in young ice hockey players. PLoS One. 2018;13(4):e0195284.
, Seasonal variation of Vitamin D levels in Swiss athletes. Schweiz Z Med Traumatol. 2016;64(1):19–25.
. Vitamin D in exercise: Physiologic and analytical concerns. Clin Chim Acta. 2013;415:45–53.
. An evaluation of the levels of vitamin d and bone turnover markers after the summer and winter periods in polish professional soccer players. J Hum Kinet. 2013;38:135–140.
. The effects of indoor and outdoor sports participation and seasonal changes on vitamin D levels in athletes. SAGE Open Med. 2019; 7: 2050312119837480.
141. , . Severely vitamin D-deficient athletes present smaller hearts than sufficient athletes. Eur J Prev Cardiol. 2015; 22(4):535–542.
, Vitamin D profile in National Football League players. Am J Sports Med. 2015;43(5):1241–1245.
. Vitamin D status is associated with adiposity in male ice hockey players. Med Sci Sports Exerc. 2014;47(3):655–661.
. Supplement use in swiss wheelchair athletes. Schweiz Z Med Traumatol. 2017;65(1):22–27.
. Vitamin D intake and sun exposure among malaysian athletes in national sports institute, Bukit Jalil. Malaysian J Med Health Sci. 2013;9(1):21–28.
. Training environment and vitamin D status in athletes. Int J Sports Med. 2013;34(3):248–252.
. Sports nutrition: Updating the practitioner. Nutrition Today. 2011;46(4):197–202.
. Female Distance Runners Training In Southeastern United States Have Adequate Vitamin D Status. Int J Sport Nutr Exerc Metab. 2016;26(5):397–403.
, . Vitamin D status and supplementation practices in elite Irish athletes: An update from 2010/2011. Nutrients. 2016;8(8).
. Association between physical activity and Vitamin D: A narrative literature review. Rev Assoc Med Bras. 2017;63(6):550–556.
. The emerging role of vitamin D in sports physical therapy: A review. Crit Rev Phys Rehabil Med. 2015;27(1):1–10.
. Impact of vitamin D in sports: Does vitamin D insufficiency compromise athletic performance? Sportverletz Sportschaden. 2017;31(1):37–44.
. Vitamin D supplementation in athletes. Nestle Nutr Inst Workshop Ser . 752013. p.109–1021.
. PTH and vitamin D. Compr Physiol. 2016;6(2):561–601.
. Why don’t serum vitamin D concentrations associate with BMD by DXA? A case of being «bound» to the wrong assay? Implications for vitamin D screening. Br J Sports Med. 2018;52(8):522–526.
. Clinical usefulness of bioavailable vitamin D and impact of GC genotyping on the determination of bioavailable vitamin D in a Korean population. Int J Endocrinol. 2019;2019:9120467.
. Vitamin D and Sport Performance. Nutrients. 2020;12(3):841.
, . Impact of vitamin D on physical efficiency and exercise performance—a review. Nutrients. 2019; 11(11).
. Vitamin D, skeletal muscle function and athletic performance in athletes—A narrative review. Nutrients. 2019;11(8).
. Low serum concentrations of 25-hydroxyvitamin D in older persons and the risk of nursing home admission. Am J Clin Nutr. 2006;84(3):616–622; quiz 71–72.
. Vitamin D supplementation, 25-hydroxyvitamin D concentrations, and safety. Am J Clin Nutr. 1999;69(5):842–856.
. Bone health in athletes: the role of exercise, nutrition, and hormones. Sports Health. 2017;9(2):108–117.
. Vitamin D deficiency among professional basketball players. Orthop J Sports Med. 2016;4(7):2325967116655742.
. Relationship between 25(OH)D levels and athletic performance in elite Polish judoists. Biol Sport. 2018;35(2):191–196.
, Health conditions detected in a comprehensive periodic health evaluation of 558 professional football players. Br J Sports Med. 2016;50(18):1142–1150.
. 25(OH)D3 levels relative to muscle strength and maximum oxygen uptake in athletes. J Hum Kinet. 2016;50:71–77.
, The impact of 1-year vitamin D supplementation on vitamin D status in athletes: A dose-response study. Eur J Clin Nutr. 2016;70(9):1009–1014.
