Emerging Options for Biologic Enhancement of Stress Fracture Healing in Athletes

Timothy L. Miller, MD; Christopher C. Kaeding, MD; Scott A. Rodeo, MD


J Am Acad Orthop Surg. 2020;28(1):1-9. 

In This Article

Vitamin D Supplementation

Much recent research has focused on identifying the role of vitamin D in preventing and healing stress fractures. Vitamin D insufficiency is likely more common among athletes than previously recognized with serum 25-hydroxycholecalciferol [25(OH)D3] level being the study of choice for identifying vitamin D deficiency and insufficiency. The ideal level for the athlete is not fully established but has been suggested to be 40 to 50 ng/mL. Shimasaki et al[47] reported that soccer players with 25(OH)D3 of <30 ng/mL had a markedly increased risk of developing fifth metatarsal stress fractures. Players with serum levels of <20 ng/mL were nearly three times as likely to develop a fifth metatarsal stress fracture. Similar results have also been reported by Davey et al.[48]

Farrokhyar et al[49] reported that 56% of 2,313 athletes surveyed had low serum 25(OH)D3 levels, with the risk of low serum vitamin D being markedly higher during winter and spring and in geographic regions higher than 40° north latitude.

Much of the research regarding vitamin D's effect on stress fractures has been conducted among military personnel. A recent systematic review and meta-analysis of 761 military personnel with stress fractures and 1,873 controls concluded that low serum 25(OH)D3 likely predisposes military personnel to lower extremity stress fractures.[50] A prospective study by Lappe et al[51] found that the average serum 25(OH)D3 concentration was markedly lower in female military recruits who had sustained a stress fracture than those without stress fractures. The same authors have suggested that calcium and vitamin D3 supplementation may have prevented a notable percentage of military recruits from sustaining a stress fracture and led to a notable decrease in the financial burden of time away from military duty.

It is currently recommended that most athletes receive at least 800 to 1,000 international units (or perhaps as much as 5,000 IU) of vitamin D3 daily. For athletes with measured low vitamin D or low bone mineral density, the therapeutic goal for supplementation should be approximately 50 ng/mL.[52] As much as 50,000 IU per week may be prescribed for individuals with severe vitamin D deficiency with minimal risk of side effects. Although recent research indicates associations between serum 25(OH)D3 and risk of stress fracture, there is currently little level-1 evidence confirming the efficacy of vitamin D supplementation for preventing and expediting the healing of stress fractures.