Routine sunscreen use led to a smaller rise in blood vitamin D
An Australian trial found a smaller vitamin D increase with routine sunscreen use than with discretionary use. The outcome was a blood measurement.
Based on the published abstract. The full paper may contain additional methods, results and limitations.
The 30-second takeaway
Routine sunscreen use produced a smaller increase in the vitamin D blood measure than discretionary use over the trial. Levels rose on average in both groups, so the result is a relative difference between sunscreen strategies rather than an average decline. The abstract does not establish that this blood-level difference caused symptoms or other health problems.
The trial was open-label. Vitamin D deficiency was an exploratory outcome, and the abstract reports no clinical health outcomes or test of whether supplements improved health.
What researchers found
Adjusted difference in blood vitamin D change
Routine versus discretionary use over approximately 1 year; 95% CI -7.2 to -3.2 nmol L-1.
What the blood result means
The primary outcome tracked change in serum vitamin D from baseline. The negative treatment effect means the routine-use group had a smaller increase than the discretionary-use group, rather than showing an average fall.
A separate exploratory result
More participants in the routine-use group met the study's blood-based definition of vitamin D deficiency at the final assessment. This was an exploratory outcome and should be distinguished from the primary analysis of concentration changes.
The original publication
Effect of daily sunscreen application on vitamin D: findings from the open-label randomized controlled Sun-D Trial.
Tran V, Duarte Romero BL, Andersen H et al.
Br J Dermatol · 2025
- PubMed ID
- 40927943
- Record checked
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