Running News Daily

Runners and stress fractures: why you should start taking vitamin D

If you’re a regular runner, you probably know someone who has had to take time out due to a dreaded stress fracture. You may have heard of pro athletes like Molly Seidel and Gabriela DeBues-Stafford taking time out for stress reactions.

Vitamin D has long been known to help the body absorb and retain calcium and phosphorus; both are critical for building bone. Recent studies have shown that vitamin D insufficiency is not only common in athletes but can be a serious factor leading to a stress fracture. Should you be taking a supplement? Here’s what you need to know.

Stress fractures v. stress reactions

Readers may be more familiar with the term “stress fracture,” which is further along the stress injury spectrum. (In other words, a stress reaction may lead to a stress fracture if left untreated.) The cause of the initial reaction (and subsequent possible fracture) is usually overuse, as opposed to more serious traumatic types of fractures from falls or other accidents.

Stress injuries are classified upon diagnosis: early (stress reaction) or late (stress fracture). A stress reaction can be considered similar to a deep bone bruise. A stress fracture is a small hairline crack in the bone.

The study

Researchers reviewed more than 180 scientific studies to determine the impact of vitamin D on musculoskeletal health and athletic performance. They found that stress fractures impact approximately 20 per cent of all athletes, both elite and amateur.

The review explores the importance of vitamin D in athletes’ diets, what type of athletes are most likely to be affected by stress fractures and what precautionary measures athletes can take. While runners of any kind were one of the most common groups sidelined by stress fractures, athletes in a wide range of load-bearing sports are affected by them.

The takeaway

We get vitamin D largely from the sun’s ultraviolet-B (UVB) rays, and many people, particularly those living above the equator, are vitamin D deficient. While only one per cent of the general population is impacted by stress fractures, one in five athletes (20 per cent) will experience one.

Vitamin D plays important role in preventing stress fractures and can be safely taken as a preventative measure. Runners should ask their doctor for regular bloodwork to check vitamin D  levels, along with calcium, creatinine and parathyroid hormone. Insufficient levels of vitamin D can be restored by optimizing your diet (while few foods naturally have much vitamin D, some are fortified with it) and taking supplements.

Work with your doctor to find the right amount of vitamin D to take: researchers determined that the prevalence of stress fractures decreased when athletes are supplemented daily with 800 IU vitamin D and 2,000 mg calcium.