Dunlin (Calidris alpina) - A medium-sized shorebird with a drooping bill, adult dunlin can be easily recognized while in breeding plumage by the large black patch on their otherwise white bellies. Familiar around the world, dunlin spend their winters up and down coastlines across the entire Northern Hemisphere.
Preformed vitamin A is found in animal products such as meat, fish, poultry and dairy foods. The other type, pro-vitamin A is found in plant-based foods such as fruits and vegetables. The most common type of pro-vitamin A is beta-carotene.
Sterols, also known as steroid alcohols, are a subgroup of the steroids and an important class of organic molecules. They occur naturally in plants, animals, and fungi, with the most familiar type of animal sterol being cholesterol. Cholesterol is vital to animal cell membrane structure and function as a precursor to fat-soluble vitamins and steroid hormones. Sterol chemical structure.