Vitamin D3 (Cholecalciferol) | CAS 67-97-0 | Bone Health

Product Name: Vitamin D3 (Cholecalciferol)
CAS No.: 67-97-0
Molecular Formula: C₂₇H₄₄O
Structure: Secosteroid skeleton with a broken B ring
Appearance: White or slightly yellowish crystals
Melting Point: 82–84 °C
Solubility: Soluble in lipids and organic solvents; practically insoluble in water
Stability: Sensitive to light, oxygen, and high temperatures; store in dark vials at 2–8 °C

1. Introduction

Vitamin D3 (cholecalciferol) is a provitamin secosteroid synthesized in the skin from 7-dehydrocholesterol under UV-B light. After two hydroxylation steps, it forms the active form calcitriol, which regulates calcium-phosphorus metabolism.

Cholecalciferol is essential for bone mineralization, normal immune system function, and regulation of cell proliferation. Deficiency leads to rickets in children and osteomalacia in adults.

2. Synthesis

• In vivo: 7-Dehydrocholesterol → (UV-B) → cholecalciferol → (liver, CYP2R1) → 25-hydroxyvitamin D₃ → (kidney, CYP27B1) → 1,25-dihydroxyvitamin D₃ (calcitriol)

• Industrial: Dehydrocholesterol followed by UV treatment and purification

3. Properties

• Appearance: White or slightly yellowish crystals

• Melting Point: 82–84 °C

• Solubility: Soluble in lipids and organic solvents; practically insoluble in water

• Stability: Sensitive to light, oxygen, and high temperatures; store in dark vials at 2–8 °C

4. Applications

• Prevention and treatment of vitamin D deficiency – doses 800–2000 IU/day for adults

• Supplements – infant formula, dairy products, and beverages

• Pharmaceuticals – osteoporosis and chronic kidney disease

5. Conclusion

Vitamin D₃ is a key prohormone for maintaining bone tissue and immune homeostasis. Adequate dosing and regular monitoring of 25-OH-D levels are necessary to prevent serious metabolic disorders.