Vitamin and Supplement Use among Old Order Amish: Sex-Specific Prevalence and Associations with Use

Complementary and alternative medicine (CAM) in the form of vitamin and supplement use is increasingly prevalent in the United States. The interplay between CAM use and use of conventional medications is not well studied. We examined this issue in Old Order Amish (OOA), a population lacking several factors known to influence supplement use, whose culture and barriers to conventional medications may result in high rates of supplement use.We characterized the patterns of supplement use in OOA, including the extent to which CAM use aggregates in families, and assessed whether higher use of supplements is associated with lower medication use.We conducted a cross-sectional study of conventional medications and supplements in 2,372 adult Amish from the Lancaster County, PA, area. Data were collected through face-to-face interviews. Supplements were subcategorized as herbal vs vitamin/mineral supplements.Seventy-seven percent of all Amish adults reported current supplement use, whereas 22% reported medication use. Women used supplements more often and used more supplements than men, and familial aggregation of supplement use was stronger in family pairs involving women. Supplement use was associated with less medication use after controlling for age, sex, body mass index, and self-reported histories of hypertension, diabetes, and hyperlipidemia (adjusted odds ratio [OR] 0.96, 95% CI 0.92 to 1.00; P=0.047). This association was driven primarily by use of herbal supplements (adjusted OR 0.94, 95% CI 0.89 to 0.99; P=0.025) as vitamin/mineral supplements were not associated with different use of medication (adjusted OR 0.99, 95% CI 0.90 to 1.09; P=0.8). In analyses limited to cardiovascular medications and cardiovascular supplements in participants with hyperlipidemia, hypertension, or diabetes, supplement use was not associated with conventional medication use.OAA, particularly women, take dietary supplements much more frequently than they use conventional medications. Use of herbal supplements is associated with less use of conventional medications, whereas vitamin/mineral supplement use is not.