叶酸
美国每日参考值（DV，成人）：400 mcg DFE · 标签常用单位：mcg DFE
美国标签以 mcg DFE（膳食叶酸当量）标示叶酸；添加了合成叶酸（folic acid）时，必须在括号内标注其 mcg 数值（21 CFR 101.9）。1 mcg DFE = 1 mcg 食物叶酸 = 0.6 mcg 合成叶酸，所以含 400 mcg 合成叶酸的补充剂标示为 680 mcg DFE，而 400 mcg DFE 的每日参考值相当于 240 mcg 合成叶酸。中国与欧盟以普通 mcg 标示叶酸。
参考摄入量
| 数值 | 美国 | 中国 | 欧盟 |
|---|---|---|---|
| 标签参考值标签上百分比的基准，由各法规规定；不是推荐摄入量 | 400 mcg DFEDV · 成人及 4 岁以上儿童1 | 400 mcg DFE; 400 mcg (or mcg DFE) from 16 March 2027 (GB 28050-2025)NRV3 | 200 mcg (folic acid)NRV5 |
| 推荐摄入量（成人） | 400 mcg DFERDA · Adults 19+2 | 400 mcg DFERNI · Adults 18+4 | 330 mcg DFEPRI6 |
| 可耐受最高摄入量 | 1,000 mcg (folic acid from supplements or fortified foods)UL · Adults 19+2 | 1000 mcg (synthetic folic acid, not natural food folate)UL · Adults 18+4 | 1000 mcg (folic acid)UL7 |
- FDA, 21 CFR 101.9(c)(8)(iv), Daily Values for adults and children 4 years and older
- NIH Office of Dietary Supplements, Folate fact sheet for health professionals (2022)
- GB 28050-2011 General rules for nutrition labelling of prepackaged foods, Appendix A nutrient reference values (NRV); unit expression revised in GB 28050-2025, Appendix A (published 16 March 2025, in force 16 March 2027) (2025)
- Chinese Nutrition Society, Chinese Dietary Reference Intakes (DRIs 2023) (2023)
- Regulation (EU) No 1169/2011, Annex XIII Part A, nutrient reference values (consolidated text) (2011)
- EFSA NDA Panel, Scientific Opinion on Dietary Reference Values for folate (2014)
- EFSA NDA Panel, Scientific opinion on the tolerable upper intake level for folate (2023)
标签值（DV、NRV）是标签上百分比背后的参考点。推荐摄入量与最高摄入量按所列机构原样引用；它们因年龄、性别与生理阶段而异，且都不是建议。