Vitamin A Test

This blood test measures the amount of vitamin A (retinol) in your bloodstream. Retinol is the primary form of vitamin A circulating in the blood. Measuring your retinol level can help assess whether you have too little or too much vitamin A.

Vitamin A is a fat-soluble nutrient that plays an essential role in many core body functions. It supports normal vision—especially in low-light conditions—helps maintain a healthy immune system, and is important for the health of skin, tissues, and mucous membranes. Because your body cannot produce vitamin A on its own, it must be obtained through diet or supplements, however, as a fat-soluble nutrient, it is generally recommended to monitor levels before and during supplement use to prevent excess.

Low vitamin A levels may be linked with vision changes (particularly difficulty seeing in low light), increased susceptibility to infections, and changes in skin or tissue health. Low levels are also associated with issues of fat malabsorption, such as in celiac disease and inflammatory bowel disease. In contrast, excessively high vitamin A levels—most often related to taking too many supplements—can also be harmful and may cause headaches, blurred vision, nausea, or dizziness. Testing can help provide clarity about your current vitamin A status so you and your healthcare provider can make informed decisions about diet, supplements, or if additional testing may be useful.

No doctor’s visit needed.

Vitamin A, also called retinol, is a fat-soluble vitamin needed for healthy eyesight, cell growth, reproduction, metabolism, and a strong immune system. Getting enough retinol is important for your heart, lungs, bones, and skin. Too little retinol may increase your risk for developing infections, weakened bones, vision problems, anemia, tiredness, or dry skin and hair.

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