Willett W, Sampson L, Bain C, Rosner B, Hennekens C H, Witschie J, Speizer F E
Am J Clin Nutr. 1981 Jun;34(6):1121-5. doi: 10.1093/ajcn/34.6.1121.
A dietary questionnaire which included items relating to the use of specific vitamin preparations was sent to a randomly selected group of 2000 female, registered nurses aged 30 to 59 yr residing in 10 states. Among the 1742 women (87%) who returned completed questionnaires, the rates of use were 38% for multiple vitamins, 4% for specific preparations of vitamin A, 23% for vitamin C, and 15% for vitamin E. Women who used specific preparations of vitamins A, C, and E generally consumed them in quantities many times greater than the RDA. Use of specific vitamin preparations was found to increase with age and was highest in California.
一份包含特定维生素制剂使用相关条目的饮食调查问卷被发送给了随机挑选出的2000名年龄在30至59岁之间、居住在10个州的注册女护士。在1742名（87%）返回完整问卷的女性中，复合维生素的使用率为38%，特定维生素A制剂的使用率为4%，维生素C的使用率为23%，维生素E的使用率为15%。使用特定维生素A、C和E制剂的女性，其摄入量通常比推荐膳食摄入量（RDA）高出许多倍。特定维生素制剂的使用被发现随着年龄增长而增加，在加利福尼亚州最高。
