Vitamin D Deficiency: A Hidden Cause of Fractures in Young Athletes

Vitamin D deficiency is common in athletes and can affect musculoskeletal health, increasing the risk of injury. Young athletes are especially vulnerable to vitamin D deficiency, says Amanda Weiss Kelly, MD, is Chief of the Division of Pediatric Sports Medicine at University Hospitals Rainbow Babies & Children’s.

“Stress fractures are an issue with vitamin D deficiency,” Dr Kelly says. “It also can be related to decreased performance or decreased muscle strength.”

Why Vitamin D Is Important

Vitamin D helps your body absorb calcium for healthy bones. It’s also important for the nervous, muscle and immune systems. Many people have vitamin D deficiency and don’t know until it shows up on a blood test. For athletes, sometimes the telltale signs present themselves as an injury or muscle fatigue.

Sources for vitamin D include sunshine, certain foods and dietary supplements. Foods rich in Vitamin D include:

• Fatty fish like tuna, sardines and salmon
• Beef liver
• Egg yolks
• Fortified milk and other dairy products

Low vitamin D levels can have many causes, including diet, certain medical conditions and medications. Dr. Kelly notes that many of the foods rich in vitamin D aren’t favorites among young people. In addition, young athletes who play indoor sports and train indoors often don’t get enough sun exposure to boost vitamin D levels. This especially is the case in colder climates.

Vitamin D and Sunlight

Vitamin D is sometimes called the “sunshine vitamin,” because ultraviolet rays from the sun trigger vitamin D production in the body.

But there’s need for caution because of skin cancer risk from unprotected sun exposure. Also, it’s hard to know how much vitamin D is being produced through sunlight because it depends on the time of year, time of day, location and skin type.

“The issue with sun exposure is we worry about skin cancer,” Dr. Kelly says. “The amount of sun exposure you need for vitamin D levels to improve is not that high, but it has to be the right time of day and you need to have a fair amount of skin exposed. When it’s 10 degrees below zero, it’s not useful because you need more of your skin exposed.”

The healthiest way to get vitamin D is through diet and supplements. Young athletes need about 600 international units (IU) of vitamin D daily.

Advice for Parents

Vitamin D deficiency can be overlooked. Dr. Kelly urges parents of young athletes to make sure their child gets a yearly checkup and to be on the lookout for risks and signs of problems.

“Pediatricians will assess them for the risk of low vitamin D,” she says. “We don’t order routine bloodwork on athletes, but if an athlete comes in and has performance issues or fatigue, or they have documented low bone density, checking vitamin D is really important. We will check people who seem to be at risk.”

Also, if a young athlete is dealing with stress fractures, low vitamin D is a possible cause that should be investigated. “Vitamin D is a common cause of stress fractures among other things, including not getting adequate calories or training errors,” says Dr. Kelly.

When a young athlete is deficient, providers may prescribe a supplement, typically 50,000 IU once a week for 8 weeks, followed by daily supplements.

Related Links

The sports medicine experts at UH Drusinsky Sports Medicine Institute and UH Rainbow Babies & Children’s are committed to providing world-class care for young athletes.