atc code a11 atc code a11 atc code a11 vitamins is a therapeutic subgroup of the anatomical therapeutic chemical classification system, a system of alphanumeric codes developed by the world health organization (who) for the classification of drugs and other medical products. subgroup a11 is part of the anatomical group a alimentary tract and metabolism. atc codes a alimentary tract and metabolism a01 stomatological preparations a02 drugs for acid related disorders a03 drugs for functional gastrointestinal disorders a04 antiemetics and antinauseants a05 bile and liver therapy a06 drugs for constipation a07 antidiarrheals, intestinal anti-inflammatory/anti-infective agents a08 antiobesity preparations, excluding diet products a09 digestives, including enzymes a10 drugs used in diabetes a11 vitamins a12 mineral supplements a13 tonics a14 anabolic agents for systemic use a15 appetite stimulants a16 other alimentary tract and metabolism products a b c d g h qi j l m n p r s v codes for veterinary use (atcvet codes) can be created by placing the letter q in front of the human atc code: for example, qa11. national issues of the atc classification may include additional codes not present in this list, which follows the who version. a11a multivitamins, combinations a11aa multivitamins with minerals a11aa01 multivitamins and iron a11aa02 multivitamins and calcium a11aa03 multivitamins and other minerals, including combinations a11aa04 multivitamins and trace elements a11b multivitamins, plain a11c vitamin a and d, including combinations of the two a11ca vitamin a, plain a11ca01 retinol (vitamin a) a11ca02 betacarotene a11cc vitamin d and analogues a11cc01 ergocalciferol a11cc02 dihydrotachysterol a11cc03 alfacalcidol a11cc04 calcitriol a11cc05 colecalciferol a11cc06 calcifediol a11cc20 combinations a11cc55 colecalciferol, combinations a11d vitamin b1, plain and in combination with vitamin b6 and b12 a11da vitamin b1, plain a11da01 thiamine (vitamin b1) a11da02 sulbutiamine a11da03 benfotiamine a11e vitamin b-complex, including combinations a11g ascorbic acid (vitamin c), including combinations a11ga ascorbic acid (vitamin c), plain a11ga01 ascorbic acid (vitamin c) a11gb ascorbic acid (vitamin c), combinations a11gb01 ascorbic acid (vitamin c) and calcium a11h other plain vitamin preparations a11ha other plain vitamin preparations a11ha01 nicotinamide a11ha02 pyridoxine (vitamin b6) a11ha03 tocopherol (vitamin e) a11ha04 riboflavin (vitamin b2) a11ha05 biotin a11ha06 pyridoxal phosphate a11ha07 inositol a11ha08 tocofersolan a11ha30 dexpanthenol a11ha31 calcium pantothenate a11ha32 pantethine a11j other vitamin products, combinations