---
title: "Vitamin A Structure (C20H30O): 3D Model, Formula & Molar Mass | MolDraw"
url: https://www.moldraw.com/molecules/vitamin-a.html
description: "Structure of Vitamin A (C20H30O, 286.46 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 A structure

# Vitamin A structure and 3D model (C20H30O)

Vitamin A (retinol) is a cyclohexene ring attached to a long chain of four conjugated all-trans C=C double bonds that ends in a CH₂OH group.

**Quick answer:** Vitamin A is **C20H30O**, molar mass **286.46 g/mol**. Long, mostly flat conjugated chain; non-polar and fat-soluble, 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 A at a glance

| Formula | C20H30O |
| --- | --- |
| Molar mass | 286.46 g/mol |
| IUPAC name | (2E,4E,6E,8E)-3,7-dimethyl-9-(2,6,6-trimethylcyclohexen-1-yl)nona-2,4,6,8-tetraen-1-ol |
| Atoms / bonds | 51 / 51 |
| H-bond donors / acceptors | 1 / 1 |
| logP (estimated) | 5.5 |
| SMILES | `CC1=C(C(CCC1)(C)C)/C=C/C(=C/C=C/C(=C/CO)/C)/C` |
| InChIKey | `FPIPGXGPPPQFEQ-OVSJKPMPSA-N` |
| PubChem | [445354](https://pubchem.ncbi.nlm.nih.gov/compound/445354) |

![2D structural formula of Vitamin A (C20H30O)](https://www.moldraw.com/molecules/img/vitamin-a.svg)

2D structure (skeletal formula) · [Draw it in MolDraw](https://www.moldraw.com/)

## What the 3D model of Vitamin A shows

The model contains **51 atoms** (21 heavy atoms and 30 hydrogens) joined by **51 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 5.5 means it is fat-loving (lipophilic). Its topological polar surface area is 20 Ų.

## Shape and bond angles

| Atom(s) | Geometry / hybridisation | Angles & lengths |
| --- | --- | --- |
| polyene chain carbons | Trigonal planar, sp²; conjugated | ≈ 120° |
| ring CH₂ and methyl carbons | Tetrahedral, sp³ | ≈ 109.5° |
| CH₂OH carbon | Tetrahedral, sp³ | ≈ 109.5° |

### Is Vitamin A polar?

No, mostly non-polar. The single OH group is small compared with the 20-carbon skeleton, so retinol is a fat-soluble vitamin.

## Elemental composition of C20H30O

| Element | Atoms | Mass (g/mol) | Mass % |
| --- | --- | --- | --- |
| Carbon (C) | 20 | 240.220 | 83.86% |
| Hydrogen (H) | 30 | 30.240 | 10.56% |
| Oxygen (O) | 1 | 15.999 | 5.59% |

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 A

- Needed for vision, growth and the immune system
- Added to foods and supplements
- Retinol and related retinoids are used in skin care

## Interesting facts

- The body makes retinol from beta-carotene, the orange pigment in carrots.
- In the eye, retinal (the aldehyde form) switches from 11-cis to all-trans when it absorbs light.
- Vitamin A was the first vitamin to be named with a letter.

**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 A?

Vitamin A (retinol) is a cyclohexene ring attached to a long chain of four conjugated all-trans C=C double bonds that ends in a CH₂OH group. Its SMILES is CC1=C(C(CCC1)(C)C)/C=C/C(=C/C=C/C(=C/CO)/C)/C.

### Why is vitamin A fat-soluble?

It is mostly a hydrocarbon with just one OH group, so it dissolves in fats and is stored in the liver.

### What is the difference between retinol and retinal?

Retinol ends in CH₂OH (an alcohol). Retinal ends in CHO (an aldehyde) and is the form used in vision.

### What is the chemical formula and molar mass of Vitamin A?

Vitamin A is C20H30O with a molar mass of 286.46 g/mol. It contains 51 atoms: 20 carbon, 30 hydrogen, 1 oxygen.

### What is the IUPAC name of Vitamin A?

The IUPAC name is (2E,4E,6E,8E)-3,7-dimethyl-9-(2,6,6-trimethylcyclohexen-1-yl)nona-2,4,6,8-tetraen-1-ol.

### How do I draw Vitamin A?

Open the MolDraw editor, paste the SMILES CC1=C(C(CCC1)(C)C)/C=C/C(=C/C=C/C(=C/CO)/C)/C or type "Vitamin A" in name search, and the structure is drawn for you. You can then export it as PNG, SVG, MOL or CDXML.

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