Evidence check: Selen in the context of Haut

The question of selenium in the context of skin is nuanced. Selenium is an essential trace element that acts as a cofactor for antioxidant selenoproteins like glutathione peroxidases, which protect skin cells from oxidative stress caused by UV radiation. However, the evidence for a benefit of selenium supplementation in well-nourished individuals is weak. The large SELECT trial (RCT) found no benefit for general health, and excess selenium is toxic (upper tolerable intake 255 µg/day per EFSA). Some consumer DNA tests highlight GPX1 variants to suggest increased selenium needs, but the effect is small and not clinically actionable. For skin-specific outcomes (e.g., acne, skin cancer prevention), observational studies show mixed results: some suggest a protective role, others find no effect or even harm at high doses. Therefore, routine selenium supplementation for skin health is not supported by strong evidence. A better approach is to ensure adequate dietary intake (e.g., Brazil nuts, fish) and, if concerned, test blood selenium levels. The evidence rating is mixed: mechanistic plausibility exists, but human data are inconsistent and not robust enough for a general recommendation.