English version in progress: interface and data are in English; some explanatory text is still in Chinese.
Vitamin C
它是水溶性抗氧化剂，也是合成胶原蛋白必需的；剂量越大吸收率越低，多余部分随尿排出。
Full ranking Dose tool Products (8,730)
Key facts
Daily Value (US FDA)90 mg
Tolerable Upper Intake Level (UL)2,000 mg
Median（Per day）100 mgP5 10 – P95 1,000
Products8,730
Sources: https://ods.od.nih.gov/factsheets/VitaminC-HealthProfessional/ · FDA DV 90 mg (https://www.fda.gov/food/nutrition-facts-label/daily-value-nutrition-and-supplement-facts-labels); pre-2016 DV [60] (https://www.federalregister.gov/documents/2016/05/27/2016-11867/food-labeling-revision-of-the-nutrition-and-supplement-facts-labels); adult UL 2000 mg; hard_high=20000 per serving (UL x10 or market maximum), hard_low=DV/1000
How it works：维生素 C 吃多了会怎样？
- 中等摄入量时 70–90% 被吸收；超过 1 g/天时，吸收率降到 50% 以下。
- 维生素 C 是抗氧化剂，参与胶原蛋白、左旋肉碱和部分神经递质的合成；它还能提高非血红素铁的吸收。
- 未被吸收或多余的部分经肾脏随尿排出。
Schematic only; positions and scale are not anatomical.
Limits and cautions：成人 UL 为 2,000 mg/天；超量常见腹泻、恶心。
Sources：NIH ODS: VitaminC Fact Sheet for Health Professionals
Daily dose across products（mg/day）
DV 90
UL 2,000
2.5 mglog scale · n=8,7303,600 mg
Label data from official national databases and brand websites, as declared; not lab-verified.
Common forms
| Form | Products | Median | P5–P95 | Elemental fraction |
|---|---|---|---|---|
| Ascorbic acid | 5824 | 101 mg | 15 – 1,000 | — |
| Mineral ascorbate (Ca/Na/Mg) | 1341 | 130 mg | 18.8 – 1,000 | — |
| Ascorbyl palmitate | 170 | 13.3 mg | 2 – 500 | — |
Top ranked
| Rank | Brand | Product | Per day | Score |
|---|---|---|---|---|
| 1 | Emergen-C | 1,000 mg Vitamin C Key Lime | 1,000 mg | 90.0 |
| 1 | The Vitamin Shoppe | Super Stress With Vitamin C | 1,000 mg | 90.0 |
| 1 | GNC | Vitamin C | 500 mg | 90.0 |
| 1 | NutraChamps | Vitamin C | 1,000 mg | 90.0 |
| 1 | The Vitamin Shoppe | Vitamin C 1000 mg | 1,000 mg | 90.0 |
For information only; not medical advice. Talk to a doctor or pharmacist before starting or stopping any supplement.