--- title: "Vitamin D3 Structure (C27H44O): 3D Model, Formula & Molar Mass | MolDraw" url: https://www.moldraw.com/molecules/vitamin-d3.html description: "Structure of Vitamin D3 (C27H44O, 384.65 g/mol): rotatable 3D model, 2D skeletal formula, IUPAC name, SMILES, shape, polarity, uses and FAQ." lang: en publisher: Scidart Academy generated: 2026-10-26 --- [MolDraw](https://www.moldraw.com/) › [3D molecule models](https://www.moldraw.com/molecules/) › Vitamin D3 structure # Vitamin D3 structure and 3D model (C27H44O) Vitamin D3 (cholecalciferol) is a secosteroid: a steroid whose B ring has been broken open by UV light. It has a conjugated triene linking a cyclohexanol ring to a two-ring system with a hydrocarbon tail. **Quick answer:** Vitamin D3 is **C27H44O**, molar mass **384.65 g/mol**. Long, flexible and mostly hydrocarbon; non-polar, fat-soluble and practically insoluble in water. Atom labels Hydrogens Spin Drag to rotate · pinch or scroll to zoom. 3D coordinates: computed with RDKit (ETKDG conformer, force-field optimised). ## Vitamin D3 at a glance | Formula | C27H44O | | --- | --- | | Molar mass | 384.65 g/mol | | IUPAC name | (1S,3Z)-3-[(2E)-2-[(1R,3aS,7aR)-7a-methyl-1-[(2R)-6-methylheptan-2-yl]-2,3,3a,5,6,7-hexahydro-1H-inden-4-ylidene]ethylidene]-4-methylidenecyclohexan-1-ol | | Atoms / bonds | 72 / 74 | | H-bond donors / acceptors | 1 / 1 | | logP (estimated) | 7.6 | | SMILES | `C[C@H](CCCC(C)C)[C@H]1CC[C@@H]\2[C@@]1(CCC/C2=C\C=C/3\C[C@H](CCC3=C)O)C` | | InChIKey | `QYSXJUFSXHHAJI-YRZJJWOYSA-N` | | PubChem | [5280795](https://pubchem.ncbi.nlm.nih.gov/compound/5280795) | ![2D structural formula of Vitamin D3 (C27H44O)](https://www.moldraw.com/molecules/img/vitamin-d3.svg) 2D structure (skeletal formula) · [Draw it in MolDraw](https://www.moldraw.com/) ## What the 3D model of Vitamin D3 shows The model contains **72 atoms** (28 heavy atoms and 44 hydrogens) joined by **74 bonds**; in ball-and-stick mode every stick is one bond, and double or aromatic bonds are drawn as multiple sticks. Switch to *space-filling* to see the molecule as its electron cloud, scaled to van der Waals radii: this is the shape other molecules actually "feel". It can donate 1 and accept 1 hydrogen bonds, and its estimated logP of 7.6 means it is fat-loving (lipophilic). Its topological polar surface area is 20 Ų. ## Shape and bond angles | Atom(s) | Geometry / hybridisation | Angles & lengths | | --- | --- | --- | | triene carbons | Trigonal planar, sp²; conjugated | ≈ 120° | | ring and side-chain carbons | Tetrahedral, sp³ | ≈ 109.5° | | C=CH₂ (exocyclic methylene) | Trigonal planar, sp² | ≈ 120° | ### Is Vitamin D3 polar? No, mostly non-polar. It has only one OH group on a 27-carbon skeleton, so it dissolves in oils and is stored in body fat. ## Elemental composition of C27H44O | Element | Atoms | Mass (g/mol) | Mass % | | --- | --- | --- | --- | | Carbon (C) | 27 | 324.297 | 84.31% | | Hydrogen (H) | 44 | 44.352 | 11.53% | | Oxygen (O) | 1 | 15.999 | 4.16% | Calculated from IUPAC standard atomic weights. Check any formula with the [molar mass calculator](https://www.moldraw.com/tools/free-chem-tools/molar-mass-calculator.html). ## Uses of Vitamin D3 - Helps the body absorb calcium for healthy bones - Added to supplements and fortified foods - Prevents rickets in children ## Interesting facts - Skin makes vitamin D3 when UVB light breaks a ring in 7-dehydrocholesterol. - The body converts it in the liver and then the kidneys into the active hormone calcitriol. - Vitamin D2 (ergocalciferol) is the plant and fungal version, with an extra double bond and methyl group in the side chain. **Drawing structures for your notes?** MolDraw is a free online chemical structure editor for molecules, reactions and lab diagrams. [Open MolDraw editor](https://www.moldraw.com/) ## Frequently asked questions ### What is the structure of Vitamin D3? Vitamin D3 (cholecalciferol) is a secosteroid: a steroid whose B ring has been broken open by UV light. It has a conjugated triene linking a cyclohexanol ring to a two-ring system with a hydrocarbon tail. Its SMILES is C[C@H](CCCC(C)C)[C@H]1CC[C@@H]\2[C@@]1(CCC/C2=C\C=C/3\C[C@H](CCC3=C)O)C. ### What is a secosteroid? A steroid in which one of the rings has been cut open. In vitamin D3 the B ring is broken between C9 and C10. ### Is vitamin D a hormone or a vitamin? Both, in a way. The skin can make it with sunlight, and its active form calcitriol works as a hormone. ### What is the chemical formula and molar mass of Vitamin D3? Vitamin D3 is C27H44O with a molar mass of 384.65 g/mol. It contains 72 atoms: 27 carbon, 44 hydrogen, 1 oxygen. ### What is the IUPAC name of Vitamin D3? The IUPAC name is (1S,3Z)-3-[(2E)-2-[(1R,3aS,7aR)-7a-methyl-1-[(2R)-6-methylheptan-2-yl]-2,3,3a,5,6,7-hexahydro-1H-inden-4-ylidene]ethylidene]-4-methylidenecyclohexan-1-ol. ### How do I draw Vitamin D3? Open the MolDraw editor, paste the SMILES C[C@H](CCCC(C)C)[C@H]1CC[C@@H]\2[C@@]1(CCC/C2=C\C=C/3\C[C@H](CCC3=C)O)C or type "Vitamin D3" in name search, and the structure is drawn for you. 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