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Articles
Short pieces on how to read reference values and where the differences come from — fully sourced.
2026-07-19 Selenium: why less means more The narrow margin between deficiency and excess — and why Brazil nuts are a special case. 2026-07-19 Salt and blood pressure: why it isn't just sodium that counts, but potassium too The WHO looks at the ratio of sodium to potassium. We explain it simply, with full sources. 2026-07-18 Why reference values differ between countries Same science, different job for the document. A short look at where the discrepancies come from. 2026-07-17 Vitamin D in winter: what the data say In summer, the skin produces vitamin D; in winter, its availability drops. What follows from that.