The document summarizes research on the relationship between UV radiation exposure, vitamin D levels, and stress fracture risk in female athletes. It finds that female athletes in areas with low annual UV radiation have a higher risk of stress fractures than those in high UV radiation areas, as UV exposure is needed for the body to naturally produce vitamin D. A lack of vitamin D can lead to lower bone density and increase stress fracture probabilities. The document reviews multiple studies that show athletes with less outdoor exposure and darker skin tones are more likely to have vitamin D deficiencies that raise their fracture risks.

1. UV RADIATION AND STRESS
FRACTURES IN FEMALE ATHLETES
Eliot Mar

2. THESIS
Female athletes in areas of low annual UV
radiation are at a higher risk than those athletes
in areas of high annual UV radiation for stress
fracture.

3. INTRODUCTION
 Vitamin D naturally produced
 Sunlight
 PTH and Calcium
 Women high risk
 Hypovitaminosis D
 20% ages 14-60 y/o
 Biological demands
 Biomechanical differences
 High physical intensity
 Military
 Sports (Rosenblom)

4. HYPOVITAMINOSIS D & STRESS FRACTURE
 Parathyroid
 Low Vitamin D
 Bone density loss
 Female Athlete Triad
 Dietary
supplementation
(Leidig-Bruckner et al)

5. MECHANISM: UV TO BONE DENSITY
IULIANO-BURNS ET AL
 Photolytic reaction
 7-dehydrocholesterol  cholecalciferol  25-
hydroxyvitamin D, (25(OH)D), or 1,25-
dihydroxyvitamin D, (1,25(OH)2D)
 VDR binding
 Absorption up
 Blood plasma calcium down
 Osteoclast suppressed
 Daily recommended amount
 75 nmol/L

6. OBSTACLES IN THE OPTIMIZATION OF BONE HEALTH OUTCOMES IN THE
FEMALE ATHLETE TRIAD
GAELE DUCHER ET AL.

7. ANTARCTIC UV EXPOSURE
IULIANO BURNS ET AL.
 UV radiation control
 Baseline vitamin D deficient
 Dietary supplementation

8. SKIN COMPLEXION AND UV ABSORPTION
SCOTT MONTAIN ET AL.
 Military and Collegiate Athletes
 White compared to black recruits
 More efficient use of vitamin D

9. VITAMIN D AND COLLEGIATE ATHLETES
TANYA M. HALLIDAY ET AL.
 Indoor and Outdoor
 PTH measured
 Outdoor = More UV
exposure
 Spring and fall > Winter
 Dietary supplementation

10. CONFOUNDING VARIABLES
 Gender predisposition
 Inconclusive supplementation results
 Geographic change
 Daily Recommended Dosages
 Overtraining
 Genetics

11. CONCLUSIONS
 Strong biochemical evidence
 Further quantitative studies
 Prehabilitation/Rehabilitation

12. REFERENCES
 Leidig-Bruckner, H. Roth, Bruckner T,
 Lorenz A, Raue F, Frank-Raue K. Osteoporos. Int. 22, 231–240.

 Barker, Tyler; Schneider, Erik D;
 Dixon, Brian M; Henriksen, Vanessa T; Weaver, Lindell K. Nutr. Rev. 68, 365–9.

 Wentz, Laurel; Liu, Pei-yang; Hay, Emily; Ilich, Jasminka Z 176, 420–431.

 Rosenblom, Christine. Nutrition Today. 48, 81-87

 Iuliano-Burns, S; Ayton, J; Hillam, S; Jones, G; King, K; Macleod, S; Seeman, E. Osterooros. Int. 23, 2461-7

 Montain, Scott J; McGraw, Susan M; Ely, Matthew R; Grier, Tyson L; Knapik, Joseph J. BMC Musculoskelet.
Disord. 14, 135.

 Borradale, David; Kimlin, Michael. Nutr. Res. Rev. 22, 118–36.

 Ducher, Gaele; Turner, Anne I; Kukuljan, Sonja; Pantano, Kathleen J; Carlson, Jennifer L; Williams, Nancy I;
Souza, Mary Jane De. 41, 587–608.

 Halliday, Tanya M; Peterson, Nikki J; Thomas, Joi J; Kleppinger, Kent; Hollis, Bruce W; Larson-Meyer, D Enette.
Med. Sci. Sports Exerc. 43, 335–43.

 McClung, James P; Karl, J Philip. Nutr. Rev. 68, 365–9.

13. QUESTIONS