Gymnast Bone Health: Stress Fractures, Calcium, Vitamin D and Fueling

Gymnast bone health is essential for a long career in the sport, and it has lasting effects for years after she retires. Bone stress injuries (stress reactions and stress fractures) are a big issue in gymnastics, and a lot of them come back to nutrition.

Many high-level gymnasts get their vitamin D checked because it’s known to help bones. But here’s what’s less well known: vitamin D only helps the body absorb calcium. She still needs enough calcium from food, and if she doesn’t get it, her body pulls calcium from her bones to keep blood levels steady. And neither one matters much if she isn’t eating enough overall.

A young high-level gymnast (roughly 10 to her early 20s) is in a critical window for building bone. Bone loss starts around age 30, and poor nutrition during adolescence has long-term effects that are only minimally reversible, like osteopenia and osteoporosis. Let’s talk about the three things that protect her bones: energy availability, calcium and vitamin D.

By Christina Anderson MS, RDN, CSP, CSSD · Updated October 2026

Gymnast bone health in 3 steps

• Eat enough. Underfueling is the biggest threat to bone health. Missing only about 300 calories a day can be enough to cause bone loss.
• Get enough calcium. Most teens need about 1,300 mg a day, or 4-5 servings of dairy or fortified foods.
• Check vitamin D. Test, don’t guess, and supplement only if needed.

Energy availability comes first

You may wonder why we’re starting with energy instead of calcium or vitamin D. Like so many parts of gymnast nutrition and performance, you can’t ignore the glaring issue of underfueling and its effects on so many of the body’s systems. (More in REDs in Gymnasts and How Many Calories Does a Gymnast Need?)

A gymnast can take all the calcium, all the vitamin D and do all the weight-bearing exercise. But if she isn’t eating enough to meet her needs, her bone density will suffer. Missing only about 300 calories a day can cause bone loss, which matters a lot in a sport with so many bone stress injuries.

• Low energy availability, or a chronic energy deficit, means there aren’t enough “building blocks” for bones to repair, recover and grow.
• Low energy availability also suppresses hormone production from the ovaries, and a lack of estrogen leads to bone loss. That’s what happens with missing periods and delayed puberty from underfueling (essentially, malnutrition).
• Low carbohydrate availability, from not eating enough overall or restricting carbs, raises inflammatory markers and increases bone loss even more.
• Enough protein is also essential for building bone.

So a gymnast can’t just “eat healthy and get enough calcium and vitamin D” to keep her bones strong. It all comes down to whether she’s getting enough nutrition to support repair, recovery, growth and adaptation to training.

Her period protects her bones

Gymnasts with amenorrhea (missing periods) have a big drop in reproductive hormones, especially estrogen. Estrogen plays an important role in building bone, so normal cycles are a key part of protecting bone density. If she hasn’t had a period by age 15, or her periods stop, that’s a red flag to see her doctor. (More in Do Gymnasts Get Periods?)

It’s often thought that birth control will “protect” the bones of a gymnast who isn’t getting her period, but this isn’t true. Studies have actually shown small negative effects on bone density in teens on birth control compared with non-users.

It’s one thing if a gymnast wants birth control for contraception or because she has heavy, painful periods. But hormonal birth control isn’t a “fix” for missing periods, especially when the cause is not eating enough (with or without disordered eating). Unfortunately, some physicians may prescribe birth control to “protect her bones” when her missing period is actually from low energy availability (hypothalamic amenorrhea) or another hormonal condition like PCOS.

Certain birth control, like the Depo-Provera shot, can also cause 5-7% bone loss from the spine and hip. That’s significant and not worth the risk for a high-level gymnast, though the loss can reverse once the shot is stopped. Because each shot lasts 3 months, take care when weighing birth control options.

Calcium: why most gymnasts don’t get enough

Most young athletes aren’t meeting their calcium needs, which is 1,300 mg a day for ages 9-18. Since the average serving of dairy or fortified plant milk has about 200-300 mg, that’s about 4-5 servings a day.

• Does your gymnast have a source of dairy at each meal?
• Does she have dairy at least 1-2 other times a day?

If not, she’s unlikely to meet her needs, especially if she doesn’t eat dairy (vegan, vegetarian, disordered eating, lactose intolerance, milk allergy or general avoidance).

Some families stop drinking milk past a certain age because of fears like “milk is inflammatory,” “humans can’t process cow’s milk” or “milk has hormones and antibiotics.” Others just don’t emphasize dairy once kids are out of the early grade-school years (or it’s “not cool” for a teen to drink milk anymore).

Is milk inflammatory?

Milk is sometimes called inflammatory because of its saturated fat. But several studies show no evidence that whole-fat dairy increases inflammatory markers. If anything, it has a small anti-inflammatory effect. As with all nutrition research, context matters. A few cups of milk a day plus yogurt and cheese is one thing. Lots of fried cheese, fast food pizza, very sugary yogurts and multiple servings of ice cream is completely different. Some observational studies link high dairy intake to acne, but again, context.

Milk allergy vs. lactose intolerance

Tolerance is a valid reason some gymnasts avoid cow’s milk. Milk has three main components that can cause symptoms like bloating, gas, diarrhea, eczema or even constipation.

Milk has two proteins, whey and casein, which are linked to infant cow’s milk protein intolerance that most kids outgrow. If not, it can become a milk allergy, and then essentially all dairy needs to be avoided. Plant milks can work, but watch for added sugar and low protein. Plant-based cheeses and yogurts offer little nutrition beyond some calories, carbs and fat. They aren’t good sources of protein, calcium or vitamin D like their dairy counterparts.

Milk also has a carbohydrate, lactose, which some people have trouble digesting. Lactose intolerance isn’t an allergy. The body makes an enzyme called lactase that breaks down lactose, and the amount of lactase drops with age and in certain ethnic groups (with high rates of lactose intolerance in people of Asian and African descent). For many, it’s about the dose. About ½ cup of milk at a time is usually tolerated, and lower-lactose foods like hard cheese, Greek yogurt and lactose-free milk and yogurt are great ways to meet calcium needs.

Vitamin D: testing, supplements and follow-up

Vitamin D is a fat-soluble vitamin found in fatty fish, eggs, fish liver oils and fortified foods like milk. The RDA is 600 IU a day, but that’s been questioned for children, teens and especially high-level athletes. The Endocrine Society’s 2011 guideline suggested kids and teens may need at least 1,000 IU a day, and adults 1,500-2,000 IU, to keep blood levels above 30 ng/mL.

The specific lab to check is 25-hydroxyvitamin D (25(OH)D). A level under 20 ng/mL is considered deficient. Some physicians order a different, similar-looking lab by accident, 1,25-dihydroxyvitamin D, but that one is only used to monitor certain conditions.

For athletes, I like to see 25(OH)D above 40 ng/mL. Many gymnasts will need a vitamin D supplement, but test, don’t guess. A random supplement may not be enough, or could be too much. It’s safe to say many gymnasts struggle to get enough vitamin D from food, so any amount from a multivitamin or vitamin D supplement should be calculated and monitored.

Heads up: the Endocrine Society’s 2024 guideline recommends against routine vitamin D testing in healthy kids and adults without a specific reason. For high-level gymnasts, though, there often IS a reason: bone stress injuries, missing periods, limited sun or a restricted diet. That’s worth discussing with her doctor.

Vitamin D3 has been more effective than D2 in some studies, so that’s my recommendation if a supplement is needed. And always choose a third-party tested supplement, like NSF Certified for Sport or Informed Choice, especially for NCAA and elite athletes.

Stress fractures and bone stress injuries

If your gymnast has had several injuries, especially stress fractures, stress reactions or broken bones, a nutrition check is essential. We’ll review her intake, discuss supplements if needed, and recommend appropriate labs her pediatrician or sports medicine physician can order. And if she’s currently injured, see What to Eat During Injury Time Off.

Frequently asked questions

Get help for your gymnast

There are several moving parts to protecting your gymnast’s bones: enough energy, enough calcium and enough vitamin D. Not sure she’s doing what she needs to protect her bone health? Start with our free masterclass or take the free Gymnast Fueling Quiz. And if you want more than a generic meal plan, The Balanced Gymnast® Program is our 1:1 program, built by a former gymnast, nationally rated NCAA/USAG judge and pediatric sports dietitian who lives and breathes this sport. We build her plan around HER: her training, her growth, her labs and the foods she actually likes, so she can close the recovery gap each and every day.