Vitamin D and sunscreen – what should you bear in mind during the summer?

Summer is the ideal time to replenish your vitamin D stores. During this season, the sun is strong enough for your skin to produce vitamin D effectively with the help of UV radiation. Nevertheless, every second person in Germany has a vitamin D deficiency even in summer. Is this because sunscreen prevents vitamin D production? And should you take vitamin D supplements in summer as a result? 

Read the answers here.

Vitamin D: How long should you spend in the sun? 

To produce enough vitamin D, you would need to spend between 5 and 25 minutes in direct sunlight between 12 and 3 p.m. during the summer, depending on your skin type. During this time, the face, hands, and parts of the arms and legs should be uncovered. In summer, it is therefore usually possible to produce sufficient vitamin D naturally. 

However, using proper sun protection is important. It helps prevent sunburn and long-term consequences such as premature skin aging, wrinkles, and skin cancer.

Can you still produce vitamin D while using sunscreen? 

In theory, sunscreen blocks vitamin D production. This is supported by laboratory studies. However, in practice, it’s different: Observational studies show that sunscreen or sun lotion has little effect on vitamin D levels in the blood. 

Possible reasons for the differing results between lab and observational studies include: 

1. In observational studies, a low sun protection factor (SPF 15) was usually tested. The higher the SPF, the less UV radiation reaches the skin. For good skin cancer protection, you should use at least SPF 30. 
2. Unlike ideal conditions in a lab, most people apply too little sunscreen or do not reapply it regularly. As a result, the sunscreen does not completely block UV rays, and some vitamin D can still be produced. 
3. Sunscreens protected differently in a usage study: creams with high UVA and low UVB protection allowed better vitamin D production. Vitamin D is produced by UVB radiation.

Who should take vitamin D in the summer? 

A vitamin D deficiency caused by sunscreen alone is unlikely. However, there are other factors that can contribute to a vitamin D deficiency in summer. The following risk groups should therefore pay special attention to their vitamin D levels: 

• People who expose little skin to sunlight are at a higher risk of vitamin D deficiency – for example, because they cover their skin completely with clothing or rarely spend time outdoors. 
• People with dark skin need to stay in the sun longer to produce the same amount of vitamin D as people with fair skin. The reason: dark skin contains more melanin, which absorbs UV radiation. 
• Older adults produce vitamin D less efficiently through the skin. 
• Babies and children have very sensitive skin and should never be exposed to direct sunlight without protection. Therefore, they produce little to no vitamin D. 
• People with severe overweight require more vitamin D. In their case, vitamin D is more extensively stored in fat tissue, making less of it available in the blood.

Conclusion: Vitamin D in Summer 

Although studies have not yet confirmed that sunscreen causes a vitamin D deficiency, there is a certain risk when using high sun protection factor (from SPF 30) and frequent reapplication. 

Those who want to ensure adequate vitamin D levels in summer despite using sunscreen can take vitamin D supplements – because sun protection should not be compromised. For risk groups in particular, vitamin D supplementation is advisable. For most people, a supplement providing 1,000 International Units per day is suitable during summer. 

If you want to know whether your vitamin D levels are sufficient, it’s best to have them measured by a healthcare professional.

Suitable FormMed Supplements

References