Stress fractures are small cracks in a bone and are a common orthopedic injury – accounting for 20 percent of visits to sports medicine clinics. It is estimated that 21 percent of adolescents will experience a stress fracture1 with 40 percent of all athletes experiencing one in their athletic career.2

As the name implies, they occur when too much strain – or “stress” – is put on a bone, which results in a hairline fracture, either from overuse or repetitive motions or from inadequate nutrition. They mostly show up in the load-bearing bones, like the foot, heel, ankle, and lower leg – including the shin, as well as the hips and lower back. Although, most commonly, stress fractures will occur in the lower body, accounting for 95 percent of cases,2 they can also occur in the hands and wrists.

Symptoms of a stress fracture include swelling and tenderness of the area and pain that worsens with use, doesn’t go away at rest, and hurts to the touch. A trip to the doctor for an exam and x-ray can confirm the presence of a stress fracture. 

Although physical activity helps strengthen bones, physically active individuals are at the highest risk for stress fractures, including those who run or participate in running-like sports, such as endurance running, track and field,3 or cross-country skiing, and those who participate in team sports like soccer, lacrosse, basketball, and tennis.

Gymnasts, figure skaters, and dancers are also at risk, not only because of tumbling or hard landings, but also because aesthetic sports tend to have a higher incidence of nutritional imbalances, which increase risk.1

High arches or flat feet, bunions, and other physical attributes of the feet, osteoporosis, a vitamin D deficiency, or being overweight or obese all increase stress fracture risk. A condition called relative energy deficiency in sports (RED-S), formerly known as female athlete triad, multiplies the risk of this injury.

A stress fracture usually requires rest, ice, compression (such as with stress fracture socks), and elevation for weeks to months, and might even involve more invasive treatments. 

To reduce your stress fracture risk from nutritional inadequacy, focus on these key nutrients.

1. Vitamin D, Vitamin K, Calcium, Magnesium

A vitamin D deficiency can put an athlete at a 24-times-greater risk for a stress fracture,4 because vitamin D is necessary to help calcium absorption in the gut and reabsorption in the kidneys.* In one retrospective study, 83 percent of individuals with a stress fracture had vitamin D blood levels below 40 ng/mL. The authors suggested that all individuals, including the general public, professional athletes, and military populations maintain a blood level of at least 40 ng/mL year-round to reduce this risk.5

Research showed calcium and vitamin D supplementation reduced the incidence of stress fractures in female soldiers.* A prospective study in young female runners showed a reduced incidence of stress fractures and increased bone mineral density with increased dietary calcium intake.*6

Magnesium is another mineral component of bone, and its blood levels are associated with bone health.* A meta-analysis found lower serum magnesium concentrations were associated with a significantly higher risk of bone fractures.*7

Because exposure to the sun is one way to maintain vitamin D levels, vitamin D levels can change depending on the season, weather, and geographical location. Test your blood vitamin D level with Thorne’s at-home Vitamin D Test – and compare your end-of-summer to end-of-winter values.

Calcium and red blood cell magnesium levels (a better indicator of magnesium status) can be measured through Thorne’s Advanced Health Panel or Essential Health Panel. 

If you know are you prone to being deficient, research shows daily supplementation of 4,000 IU or more vitamin D is one way to achieve a blood level of 40 ng/mL.8 Thorne’s D 5,000 can help you achieve an optimal blood level of vitamin D.* 

Vitamin K works synergistically with vitamin D to promote bone formation and mineralization, and can both be acquired in Thorne’s Vitamin D + K2 liquid.* For calcium and magnesium, Thorne has several options to choose – including formulas that provide both essential minerals in either capsule or powder form.

2. Iron

Research shows a low iron level reduces bone strength.9 In one military cohort, female soldiers with a stress fracture from training had a significantly higher prevalence of anemia and iron deficiency compared to females without injury.10

Studies have found dietary iron can have a protective effect on spinal bone in postmenopausal women, a load-bearing bone and likely site for stress fractures.*11  

Iron deficiency is common in many populations depending on physical activity, metabolism, diet, absorption, and even genetics. But iron can be a difficult mineral to supplement without knowing how to get started and how to optimize dietary intake. 

Thorne’s Iron Bisglycinate is a well-absorbed form of iron that is easy on the gastrointestinal system. Thorne’s Ferrasorb includes B vitamin cofactors and vitamin C to optimize iron’s absorption.

3. Creatine

Creatine is typically noted as a nutrient in foods or supplements that helps maintain muscle mass.* Because loss of muscle mass (sarcopenia) is clinically associated with bone loss, creatine is a nutrient that helps maintain bone health too.* The research shows creatine has positive effects on osteoblast activity, the cells involved in building bones.* There is also literature that suggests creatine helps prevent bone breakdown.*12

In one study, healthy older males who supplemented with creatine (0.1 gram per kilogram of body weight daily, which equaled about 9 g daily) for 10 weeks in combination with whole-body resistance training three times a week showed a significant (25 percent) reduction in an indicator of bone breakdown compared to an increase (10 percent) for consuming a placebo.13 Although this study didn’t look at stress fractures, creatine can play a role in helping to build and maintain optimal bone health.*

Thorne’s Creatine powder delivers a highly researched form of creatine monohydrate that can be consumed according to one’s needs, and it mixes well with other foods or supplements. 

4. Vitamin C and Collagen

Even with a healthy diet, stress fractures can still occur because of a biomechanical cause, like a heel strike of a foot on uneven pavement, or not wearing proper supportive footwear, or standing on hard surfaces for long periods of time.

Bones are almost 40 percent collagen, which makes collagen important for maintaining bone structure and strength. The research shows that vitamin C has the potential to accelerate bone healing after a fracture, increase type I collagen synthesis that structures the bone, and reduce oxidative stress markers.*14 Therefore vitamin C supplementation alone or in combination with collagen should be considered to support bone healing.*

Thorne has an unflavored Collagen Fit powder that provides 15 g of collagen types I (specifically for bone support) and III per serving. Pair that with one of the many options that contains vitamin C for optimal support to help bone strength and get you moving again.*

References

  1. Beck B, Drysdale L. Risk factors, diagnosis and management of bone stress injuries in adolescent athletes: a narrative review. Sports (Basel) 2021;9(4). doi:10.3390/sports9040052
  2. Abbott A, Bird ML, Wild E, et al. Part I: epidemiology and risk factors for stress fractures in female athletes. Phys Sportsmed 2020;48(1):17-24.
  3. Fredericson M, Jennings F, Beaulieu C, Matheson GO. Stress fractures in athletes. Top Magn Reson Imaging 2006;17(5):309-325.
  4. Knechtle B, Jastrzębski Z, Hill L, Nikolaidis PT. Vitamin D and stress fractures in sport: preventive and therapeutic measures – a narrative review. Medicina 2021;57(3). doi:10.3390/medicina57030223
  5. Miller JR, Dunn KW, Ciliberti LJ Jr, et al. Association of vitamin D with stress fractures: a retrospective cohort study. J Foot Ankle Surg 2016;55(1):117-120.
  6. Tenforde AS, Sayres LC, Sainani KL, Fredericson M. Evaluating the relationship of calcium and vitamin D in the prevention of stress fracture injuries in the young athlete: a review of the literature. PM R 2010;2(10):945-949.
  7. Dominguez LJ, Veronese N, Ciriminna S, et al. Association between serum magnesium and fractures: a systematic review and meta-analysis of observational studies. Nutrients 2023;15(6). doi:10.3390/nu15061304
  8. Burgi AA, Gorham ED, Garland CF, et al. High serum 25-hydroxyvitamin D is associated with a low incidence of stress fractures. J Bone Miner Res 2011;26(10):2371-2377.
  9. Yang J, Li Q, Feng Y, Zeng Y. Iron deficiency and iron deficiency anemia: potential risk factors in bone loss. Int J Mol Sci 2023;24(8). doi:10.3390/ijms24086891
  10. Yanovich R, Merkel D, Israeli E, et al. Anemia, iron deficiency, and stress fractures in female combatants during 16 months. J Strength Cond Res 2011;25(12):3412-3421.
  11. Abraham R, Walton J, Russell L, et al. Dietary determinants of post-menopausal bone loss at the lumbar spine: a possible beneficial effect of iron. Osteoporos Int 2006;17(8):1165-1173.
  12. Cordingley DM, Cornish SM, Candow DG. Anti-inflammatory and anti-catabolic effects of creatine supplementation: a brief review. Nutrients 2022;14(3). doi:10.3390/nu14030544
  13. Candow DG, Little JP, Chilibeck PD, et al. Low-dose creatine combined with protein during resistance training in older men. Med Sci Sports Exerc 2008;40(9):1645-1652.
  14. DePhillipo NN, Aman ZS, Kennedy MI, et al. Efficacy of vitamin C supplementation on collagen synthesis and oxidative stress after musculoskeletal injuries: a systematic review. Orthop J Sports Med. 2018;6(10):2325967118804544.