Importance of Vitamin D for Athletes: A Sports Dietitian’s Guide

As athletes, you spend countless hours training, recovering, and fine-tuning your nutrition to perform at your best. But one nutrient that often slips under the radar is vitamin D. Known as the “sunshine vitamin,” it’s not only essential for bone health - it also supports muscle strength, recovery, and immunity.

At Nutrition & Co., we believe that, maintaining optimal vitamin D levels is critical for performance and overall well-being especially during the colder months. Let’s explore why vitamin D matters for athletes, how to identify risk factors for deficiency, and practical dietetic strategies to ensure you’re getting enough.

What is Vitamin D and Why Does It Matter for Athletes?

Vitamin D is a fat-soluble vitamin that helps your body absorb calcium and phosphorus, both essential for strong bones and muscle function. Unlike many nutrients, vitamin D can be synthesised in your skin when exposed to sunlight.

For athletes, this nutrient isn’t just about bone health - it’s tied directly to:

• Performance outcomes (strength, speed, and power)

• Injury prevention (lower stress fracture risk)

• Immune resilience (fewer training disruptions due to illness)

• Recovery (faster bounce-back after intense sessions)

At Nutrition & Co., we often find that athletes underestimate the role of vitamin D until they’re sidelined by fatigue, illness, or injuries that could have been prevented.

Vitamin D and Athletic Performance

Bone Health and Injury Prevention

Athletes put their skeletal systems under repeated strain. Adequate vitamin D helps regulate calcium metabolism, reducing the risk of stress fractures and bone-related injuries — common in sports like running, gymnastics, and basketball.

Muscle Function and Strength

Research shows that vitamin D influences muscle contraction and power. Athletes with optimal levels often demonstrate improved balance, explosive movements, and endurance — all of which translate into better on-field or in-gym performance.

Immunity and Training Consistency

Heavy training loads can temporarily suppress the immune system. Vitamin D strengthens immune defences, helping athletes avoid illnesses that interrupt their training cycles.

Recovery and Inflammation Control

Vitamin D plays a role in reducing exercise-induced inflammation. This means faster recovery between training sessions and less muscle soreness, which is key to consistent progress.

Why Athletes Are at Higher Risk of Deficiency?

Even dedicated athletes often fall short on vitamin D. Here are common dietitian-identified risk factors:

• Indoor training routines (swimmers, gymnasts, and hockey players often miss natural sun exposure).

• Living in northern climates with long winters and limited UVB sunlight.

• Darker skin tones naturally produce less vitamin D from sunlight.

• Dietary restrictions (vegan or dairy-free diets may lack fortified foods and natural vitamin D sources).

• High sunscreen use protects skin but reduces vitamin D synthesis.

Athletes with deficiencies may notice fatigue, frequent illness, slower recovery, or more frequent injuries.

How Much Vitamin D Do Athletes Need?

From a sports dietitian’s standpoint, the general recommendation for adults is 600–800 IU/day, but athletes often need more to maintain optimal performance levels.

• Target blood levels: 30–50 ng/mL (serum 25-hydroxyvitamin D).

• Some athletes may require higher intakes — especially those training indoors or in winter months.

💡 Pro tip: Routine blood tests are the gold standard. A dietitian or sports physician can interpret results and design a personalised plan.

Best Sources of Vitamin D for Athletes

1. Sunlight Exposure

• Aim for 10–30 minutes of sun exposure, 2–3 times per week, depending on skin tone and location.

• Outdoor training sessions are a natural way to combine activity with vitamin D synthesis.

2. Dietary Sources

Dietitians encourage athletes to include:

• Fatty fish: salmon, mackerel, tuna, sardines

• Egg yolks

• Fortified dairy or plant-based milk

• Fortified cereals and juices

3. Supplementation

For many athletes, especially in winter or when training indoors, supplements are necessary. Vitamin D3 (cholecalciferol) is generally preferred over D2.

Always consult with a registered dietitian or sports physician to determine:

• Appropriate dosage

• Timing of intake (with meals for better absorption)

• Whether to combine with calcium for bone support

Frequently Asked Questions (FAQ)

1. Should athletes take vitamin D supplements year-round?

Not always. Athletes in sunny climates who regularly train outdoors may not need supplements during summer. However, for those in colder regions or with limited sun exposure, year-round supplementation may be beneficial under professional supervision.

2. Can vitamin D improve my athletic performance?

Yes — research suggests adequate vitamin D levels support muscle strength, reduce fatigue, improve recovery, and lower injury risk. While it’s not a magic pill, it’s a foundational nutrient for performance.

3. What’s the safest way to check my vitamin D status?

A simple blood test (serum 25-hydroxyvitamin D) is the most accurate method. From there, a sports dietitian or physician can guide you on diet, sunlight, and supplementation strategies tailored to your needs.

Interested in taking your nutrition to the next level? Book an initial appointment with our team of dietitians today on WhatsApp via +447888465215.