Selenium is an ingredient in many multivitamins and other dietary supplements, including infant formula. Biotin is also available in dietary supplements, individually or as an ingredient in multivitamins. Many multivitamins now contain vitamin D in different amounts. Flintstones Chewable Vitamins are supplemental multivitamins for children based on the animated sitcom "The Flintstones". It is worth noting that many multivitamins do not contain the Adequate Intake of choline. Most multivitamins come in capsule form; tablets, powders, liquids, and injectable formulations also exist. Multivitamins that do not interact with clotting are available for patients on anticoagulants. Multivitamins often contain cyanocobalamin, which is presumably converted to bioactive forms in the body. Centrum is a brand of multivitamins produced by Pfizer (formerly Wyeth). He has been a commercial spokesman for Centrum multivitamins and Cardiotech fitness equipment. Ritual manufactures and distributes multivitamins for women. The therapy he used anticipates the use today of multivitamins in ARMD patients. Multivitamins are the most commonly used product. The need for high-quality studies looking at the safety of taking multivitamins has been highlighted. Stacy also produced "Stacy-Pak" multivitamins.