Table 1.
Five possible models of ascorbic acid requirements
| Source (ref.) | Mean requirement, mg per day | SD of requirement, mg per day | RDA*, mg per day | Criteria used for nutritional adequacy |
|---|---|---|---|---|
| 1989 FNB/NRC (1) | 46 | 7 | 60 | Depletion rate and turnover at |
| a pool size of 1500 mg; 85% | ||||
| absorption at usual intake. | ||||
| Levine et al. (3) | ||||
| Model 1 | 77 | 11.5 | 100 | Monocyte and lymphocyte |
| Model 2 | 100 | 15 | 130 | maximum ascorbic acid |
| concentration. | ||||
| Model 3 | 154 | 23 | 200 | Bioavailability; plasma |
| ascorbic acid concentration; | ||||
| Model 4 | 200 | 30 | 260 | considerations of vitamin C |
| function. |
*
RDA taken to be the mean requirement + 2 SD of requirement.