Table 4. Content of vitamin D2 in sunlight and UV light exposed shiitake
| Exposed method | Food name | | Type | Exposed time (h) | Concentration2) (μg/kg) |
| Vitamin D2 |
| Sunlight from outdoor | Raw shiitake (whole) | | Wrapped | 0.5 | ND1) |
| | 1 | 16.7 |
| ∩3) | 0.5 | ND |
| | 1 | 7.5 |
| ∪4) | 1 | 52.8 |
| Sunlight from indoor | Raw shiitake (whole) | | Wrapped | 0.5 | ND |
| | 1 | ND |
| | ∩ | 0.5 | ND |
| | 1 | ND |
| | 3 | 7.42 |
| ∪ | 0.5 | 24.4 |
| | 1 | 25.8 |
| | 3 | 29.5 |
| UV light | Dried shiitake (whole) | A | Whole | 0 | 4.7 |
| ∩ | 0.5 | 115.7 |
| ∪ | 0.5 | 235.4 |
| B | Whole | 0 | 3.2 |
| ∩ | 0.5 | 102.3 |
| ∪ | 0.5 | 223.5 |
| C | Whole | 0 | ND1) |
| ∩ | 0.5 | 88.4 |
| ∪ | 0.5 | 104.4 |
| UV light | Dried shiitake (sliced) | D | Sliced | 0 | 67.3 |
| Sliced | 0.5 | 394.4 |
| E | Sliced | 0 | ND |
| Sliced | 0.5 | 206.6 |
| F | Sliced | 0 | ND |
| Sliced | 0.5 | 167.9 |
ND, not detected.
Moisture correction concentration.
∩, shiitake top.
∪, shiitake bottom.