DHA: 1. Docosahexaenoic acid, an essential fatty acid, thought to be important to the development of infants, particularly as regards their eyes and brain. DHA is present in breast milk and has been added to some infant formulas. Postnatal DHA may improve vision and some cognitive functions in infants and toddlers. DHA is an omega-3, polyunsaturated, 22-carbon fatty acid. It is present in abundance in certain fish (such as tuna and bluefish) and marine animal oils.
2. Dihydroxyacetone, the active ingredient in sunless or self-tanning lotions. DHA is a colorless sugar that darkens the skin by staining. It interacts with the dead surface cells found in the epidermis, or the outermost layer of the skin, producing a color change. As the dead skin cells are naturally sloughed off, the color gradually fades, typically within 5 to 7 days of application. People using DHA should be protected from exposure to the entire area of the eyes, the lips and all parts of the body covered by mucous membrane, and from internal exposure caused by inhaling or ingesting the product.