Which one is associated with vitamin D

Options

A. Tocopherol
B. Ergosterol
C. Cholesterol
D. Both B and C

Explanation

To determine which substances are associated with vitamin D, we can analyze the options provided:

1. **Understanding Vitamin D**:
- Vitamin D is a fat-soluble vitamin that is crucial for maintaining bone health and calcium metabolism.

2. **Analyzing the Options**:
- **Tocopherol**: This is a form of vitamin E, which is not associated with vitamin D. Therefore, it can be eliminated as an option.
- **Ergosterol**: This compound is a sterol found in fungi and is a precursor to vitamin D2 (ergocalciferol). Thus, it is associated with vitamin D.
- **Cholesterol**: This is a sterol found in animal cells and is a precursor to vitamin D3 (cholecalciferol). Therefore, it is also associated with vitamin D.
- **Both B and C**: Since ergosterol (B) and cholesterol (C) are both associated with the production of forms of vitamin D, this option is valid.

3. **Conclusion**:
- Based on the analysis, the correct answer is **both B and C** (ergosterol and cholesterol) because both are precursors to different forms of vitamin D.

### Final Answer:
The substances associated with vitamin D are **both B and C** (ergosterol and cholesterol).