Plain-language: What is the vitamin D upper limit about (and why it matters for pet food)? (EN+ZH)

EN — For pet owners. EFSA (Europe's food-safety science panel) set tolerable upper intake levels (UL) for vitamin D — the most you should get daily without risk. The numbers: UL for vitamin D is 100 μg/day for adults; UL is 50 μg/day for children up to 10 years; for infants 25 μg/day (up to 6 months) and 35 μg/day (6–12 months). These limits derive from a NOAEL of 250 μg/day for hypercalcaemia in adults — too much vitamin D pushes blood calcium too high. Why pet owners should care: vitamin D is a fat-soluble nutrient with a narrow safety margin in dogs and cats, and Vitamin D is routinely added to dog and cat foods. Bottom line — vitamin D overdose is a real risk for pets; the human UL frames the same safety thinking behind pet-food maxima.

中文 — 给宠物主人。 EFSA（欧洲食品安全科学机构）为维生素 D 设定了可耐受最高摄入量（UL，每天不超过此量才安全）。数字：UL for vitamin D is 100 μg/day for adults（成人 100 μg/天）；UL is 50 μg/day for children up to 10 years（10 岁以下儿童 50 μg/天）；婴儿 25 μg/day (up to 6 months) 和 35 μg/day (6–12 months)。这些上限源自 NOAEL of 250 μg/day for hypercalcaemia in adults（维生素 D 过量会使血钙过高）。宠物主人为什么要关心：vitamin D is a fat-soluble nutrient with a narrow safety margin in dogs and cats（维生素 D 是脂溶性，在猫狗身上安全余量窄），且 Vitamin D is routinely added to dog and cat foods（常规添加进犬猫粮）。结论——维生素 D 过量对宠物是真风险；人体 UL 与宠物食品上限背后是同一套安全逻辑。

Source topic: EFSA_NDA_vitamin_D_UL (C1-verified against EFSA Journal 2023;21(7):8145 XML).

Claims (verified as substrings of the C1-verified source topic)

• UL for vitamin D is 100 μg/day for adults
• UL is 50 μg/day for children up to 10 years
• 25 μg/day (up to 6 months)
• 35 μg/day (6–12 months)
• NOAEL of 250 μg/day for hypercalcaemia in adults
• vitamin D is a fat-soluble nutrient with a narrow safety margin in dogs and cats
• Vitamin D is routinely added to dog and cat foods