Newcastle Study Finds 72% With Darker Skin Stayed Vitamin D Low Despite Summer Sun
Updated
Updated · ScienceAlert · Jul 18
Newcastle Study Finds 72% With Darker Skin Stayed Vitamin D Low Despite Summer Sun
1 articles · Updated · ScienceAlert · Jul 18
Summary
299 UK participants tested from December 2024 to August 2025 saw vitamin D levels barely improve into summer, despite the season when recovery would normally be expected.
72% of adults with darker skin and nearly 55% of adults 65 and older remained below the recommended threshold, pointing to the groups most affected.
Age, melanin and northern England's weaker UVB exposure likely limited vitamin D production, the researchers said, even as sunlight increased.
The study excluded supplement users and enrolled only people already low in vitamin D, so it does not estimate population-wide deficiency rates.
UK guidance already advises 400 IU daily from October to March, and the authors said higher-risk groups may need year-round supplementation.