Vitamin D deficiency is a growing concern in the UK, with experts linking the trend to increased sunscreen use and reduced consumption of fatty foods. According to recent data, 40% of Europe's population lacks sufficient vitamin D, a micronutrient crucial for immune function, bone health, and disease prevention.
The body produces vitamin D when skin is exposed to sunlight, but widespread use of high-SPF sunscreens may be hindering this process. The Spanish Society for Bone and Mineral Metabolism Research recommends light-skinned individuals expose face and arms to the sun for 15 minutes daily between March and October, using SPF 15-30 sunscreen. For elderly and osteoporosis patients, 30 minutes is advised.
Dietary sources such as oily fish, full-fat dairy, and fortified plant milks can help, but many Britons are not consuming enough. Serum levels of 25-hydroxyvitamin D below 12 ng/mL indicate deficiency, while 12-20 ng/mL is insufficient. Optimal levels are above 20 ng/mL for the general population and 30 ng/mL for those over 65 or with bone conditions.
Over-supplementation poses risks too. Doses exceeding 4,000 IU per day can lead to hypervitaminosis D, with levels above 100 ng/mL causing toxicity. A 2022 meta-analysis found that 1,000-2,000 IU daily supplements did not improve immune function in healthy individuals, though they may benefit those with deficiency.
Experts urge a balanced approach: moderate sun exposure, dietary intake, and supplements only when necessary. Pregnant women, children, the elderly, and people with darker skin are most at risk of deficiency.
