Table 4.
Reported conversion factors and bioefficacy for β-carotene from vegetables and fruits.
| Food | Conversion factora | Bioefficacy (%)b |
|---|---|---|
| Synthetic β-carotene in oil | 2.1:1–3.8:1 | 26–48 |
| Fruits | 12:1 | 8.3 |
| Tubers | 2.8:1–13.4:1 | 7.5–36 |
| Cooked vegetables | 10:1–28:1 | 1–3.5 |
| Raw vegetables | 13:1–77:1 | 0.01–7.7 |
a
Amount (μg) of ingested β-carotene required from the food source to form 1 μg of retinol.
b
Proportion of ingested β-carotene that is absorbed and converted to retinol. Based on: Van Loo-Bouwman et al., Br J Nutr 2014 (104).