Vitamin D Status, Calcium Intake, And Bone Mineral Density In High School Basketball Players.

Adolescence is an important time for bone mass accrual with bone mineral density (BMD) reaching its peak by the mid to late twenties. Recent studies have shown that basketball players are at an increased risk of vitamin D insufficiency which may impact BMD especially during this critical growth period. PURPOSE: 1) Determine if there are seasonal changes in vitamin D status and BMD over the course of the high school season, 2) assess any differences between ethnicities and sexes in BMD, vitamin D, and calcium intake. 3) determine if BMD, vitamin D, or calcium intake correlate to a history of stress fractures. METHODS: Male (n = 30) and female (n = 15) basketball players (13-19 y) were recruited from IMG Academy in Bradenton, FL. BMD (DEXA), vitamin D3 (ZRT Laboratory, Beaverton, OR), and calcium intake (Loyola Marymount Rapid Assessment Method) were measured pre-, mid-, and post-season. History of stress fracture was assessed via health questionnaire. RESULTS: BMD (p = 0.001) and vitamin D (p < 0.001) were significantly higher post season compared to pre- and mid. BMD was not different at any time point between sexes however, females’ maturity offset was significantly higher than males (p < 0.001), indicating that they were further away from peak height velocity. Black players had significantly higher BMD at every time point compared to white players (p < 0.001). Conversely, white players had significantly higher vitamin D status than black players (p < 0.001). Calcium intake was not different across the three visits (p = 0.43) but males (1,209 + 46 mg) had significantly higher intake of calcium than females (747 + 62 mg) (p < 0.001) and white players (1,145 + 47) had higher calcium intakes than black players (920 + 58) (p = 0.004). BMD was significantly correlated to a history of stress fractures (p < 0.001), but vitamin D status (p = 0.18) and calcium intake (p = 0.72) were not. CONCLUSIONS: Vitamin D status changed over the course of a basketball season despite living at a latitude that provides adequate sunshine year-round. In agreement with other studies, blacks athletes had lower vitamin D than white athletes but higher BMD. As others have suggested, measurement of vitamin D3 in black athletes may not accurately reflect status. All groups fell short of the DRI recommendation of 1,300 mg calcium /day for teenagers. All authors are employed by PepsiCo.