Can Exercise Boost Vitamin D?

Key Takeaways:

• Regular endurance-type exercise appears to raise or help maintain circulating 25-hydroxyvitamin D [25(OH)D] levels in people who are vitamin D deficient, though the effect is less clear in those already sufficient.
  
  
• The mechanism may involve exercise-induced lipolysis, releasing vitamin D stored in adipose tissue, and increased muscle-based vitamin D utilisation, but sunlight exposure and baseline status remain major factors.
  
  
• Exercise alone should not be relied upon as a substitute for adequate sunlight, diet or supplementation to maintain optimal vitamin D.

When adolescent soccer players performed high-intensity exercise, their blood levels of 25-hydroxyvitamin D (25(OH)D) increased just 15 minutes post-exercise (R). In other words, exercise may do more than burn calories and build muscle, it may also influence how your body handles vitamin D. 

In this blog, we’ll explore whether exercise can boost vitamin D, how that might work, and what it means for you as you pursue a healthy, longevity-focused lifestyle.

How does vitamin D normally work?

Before we talk about exercise and vitamin D, let’s briefly cover how vitamin D is created and measured in your body.

Vitamin D₃ (cholecalciferol) is produced in the skin when ultraviolet-B (UVB) sunlight hits 7-dehydrocholesterol. It is also ingested via foods or supplements. The liver converts it into 25-hydroxyvitamin D (25(OH)D) – the main circulating form, and the form used as a status marker (R). 

Then the kidney and other tissues convert 25(OH)D into the active form 1,25-dihydroxyvitamin D (1,25(OH)₂D), which interacts with the vitamin D receptor (VDR) in many tissues (R) 

 

Because vitamin D is fat-soluble, it’s stored in adipose tissue and also in muscle (R). Given that sunlight exposure, diet, and supplement intake are the main levers for vitamin D status, you might wonder: what role could exercise play?

What evidence links physical activity to vitamin D levels?

Observational studies

Many cross-sectional studies show a positive association between higher physical activity levels and higher serum 25(OH)D concentrations (R). For example, one systematic review reported that adults with higher physical activity had higher vitamin D levels, even after adjusting for time outdoors (R). 

Intervention/experimental studies

However, moving from correlation to causation is challenging. Some human studies of exercise interventions tested whether exercise alone can raise 25(OH)D.

• A pilot study found that in 26 adolescent boys (around 13 years old) one bout of maximal or high-intensity exercise increased 25(OH)D₃ immediately, at 15 minutes and 1 hour post-exercise (R).
  
  
• A broader review found that endurance training can significantly increase serum 25(OH)D in people who are vitamin D deficient (<50 nmol/L), but not necessarily in those already sufficient (R).
  
  
• On the flip side, a 2024 meta-analysis concluded that physical activity does not lead to increased 25(OH)D independently of time outdoors (i.e., sun exposure likely still drives the effect) (R).
  
  
• Yet a recent indoor exercise study (10 weeks, overweight adults) found exercise helped prevent the seasonal drop in vitamin D during winter – even without sunlight change or weight loss (R).
  
  

Summary of evidence

Yes – there is evidence that exercise (especially endurance forms) may boost or preserve 25(OH)D, particularly when baseline status is low, or sun exposure is limited. But exercise is not a universal or standalone “vitamin D boost” in all situations.

What kinds of exercise make the difference?

Now let’s dive deeper into what type of exercise appears to affect vitamin D levels, and under what conditions.

Endurance (aerobic) exercise

The greatest experimental evidence comes from endurance training (e.g., cycling, running) rather than resistance (weight training). For example, the larger review noted that chronic endurance exercise increased 25(OH)D in deficient subjects; resistance training did not (R). 

Resistance (strength) training

Resistance training shows mixed results. Some studies found no change, others even found reductions in 25(OH)D with strength training alone (R). 

 

Exercise intensity, status and sunlight interplay

Several factors appear to moderate the effect:

• Baseline vitamin D status: those who are deficient see more benefit.
  
  
• Sun or outdoor exposure: If you’re already getting lots of sun, the incremental gain from exercise is smaller.
  
  
• Body fat/adiposity: Higher adipose tissue means more storage/sequestration of vitamin D and less mobilisation.
  
  
• Exercise timing and fasting vs fed state may matter for metabolic effect and lipolysis.
  
  
• Sex and age may also influence responses. 

Proposed biological mechanisms: How might exercise affect vitamin D?

Let’s consider how, mechanistically, exercise might boost or preserve vitamin D status.

Lipolysis and release from adipose tissue

Endurance exercise increases fatty-acid mobilisation (lipolysis). Because adipose tissue stores vitamin D metabolites, lipolysis may release vitamin D into circulation (R). 

Muscle tissue storage and release

Skeletal muscle is increasingly recognised as a depot for 25(OH)D; exercise may promote turnover and release of vitamin D from muscle cells (R). 

Increased utilisation in target tissues

Exercise can up-regulate VDR (vitamin D receptor) expression and activity in muscle, so greater utilisation of vitamin D might shift the equilibrium of circulating concentrations (R). 

Seasonal/behavioural effects

Exercise may enable you to spend more time outdoors (even indoors vs outdoors), but some studies show indoor exercise still preserves vitamin D – implying mechanisms beyond sun exposure (R). 

 

Summary of mechanisms

Together, these suggest that exercise may “free up” stored vitamin D and/or increase demand in tissues, helping raise or maintain serum 25(OH)D — but only to a point, and depending on status and other factors.

Implications for you and your healthy ageing lifestyle

So what does all this mean in practical terms for you, especially if you’re focused on longevity and healthy ageing?

Don’t abandon sunlight, diet or supplementation

Despite exercise’s potential benefit, the majority of vitamin D is still derived from UVB skin production and intake. Exercise is an adjunct — not a replacement.

Use exercise as part of a holistic strategy

If your vitamin D status is low, and/or you live in a region with limited sun, incorporating regular endurance-type exercise (e.g., brisk walking, cycling) may help preserve your 25(OH)D levels and make your vitamin D strategy robust.

Consider your baseline status, body composition and training type

If you’re already sufficient, indoors all winter, or heavily adipose, the exercise effect may be less dramatic. In those cases, supplementation or dietary intake remains key.

Mind the seasonal dip

A recent indoor exercise intervention revealed that overweight/obese adults who participated in 4 sessions/week for 10 weeks experienced a smaller decline in vitamin D during winter compared to non-exercisers, despite not undergoing weight loss or supplementation. (R) 

Ageing and muscle/adipose interplay

As we age, body composition changes (less muscle mass, more adipose), sunlight synthesis of vitamin D declines, and the ability to mobilise stored vitamin D may be reduced. Exercise may help counteract some of these age-related changes in vitamin D metabolism, although research is still emerging.

Practical tips for boosting vitamin D with exercise (and other strategies)

Here are some actionable, evidence-informed suggestions you can apply.

1. Combine endurance workouts – aim for regular aerobic activity (e.g., 30-60 min, moderate to vigorous) a few times per week; this may help mobilise vitamin D.
   
   
2. Use seasons to your advantage – in winter months when sun exposure is low, indoor aerobic training may help offset declines.
   
   
3. Keep ambient sun exposure in mind – if you can safely get some sunlight (while balancing skin-cancer risk), it supports vitamin D production that exercise may enhance.
   
   
4. Maintain muscle mass and limit excess adiposity – because muscle and fat both play roles in vitamin D storage/mobilisation, a combined strength + aerobic approach may help overall metabolic health (even if strength training alone doesn’t raise 25(OH)D).
   
   
5. Check your vitamin D status – especially if you live in Melbourne, have low sun exposure, are ageing, or have higher adiposity; the serum 25(OH)D test gives clarity.
   
   
6. Adopt a holistic approach – diet (e.g., fatty fish, fortified foods), safe sun exposure, supplementation (when needed) and exercise together provide the best buffer for vitamin D health.

Can exercise boost vitamin D?

In short: yes, exercise can help boost or maintain vitamin D levels under the right conditions — especially for those who are deficient, training aerobically, and/or living in low-sun environments. But it’s not a standalone silver bullet. For a longevity-focused lifestyle, consider exercise as one pillar in your vitamin D strategy, alongside sun, diet and sensible supplementation.

If you’d like to learn more about how nutrition, exercise and lifestyle habits play together to support healthy ageing, read our next blog: Evidence-Based Habits to Increase Lifespan.