Vitamin supplement usage and nutritional knowledge in a sample of Portuguese health science students

The prevalence of vitamin supplement use and its relationship with nutritional knowledge was assessed in a cross-sectional study conducted between October 1998 and January 1999 in a sample of 610 health science students (179 men and 431 women) from a private institution in Portugal. Overall, the prevalence of vitamin supplement use was 16% (20% in men and 14% in women, P <0.05). Vitamin C was the supplement most frequently consumed, followed by B vitamins. Vitamin supplements were acquired in pharmacies and seldom in dietary product stores. No differences were found between vitamin supplement users and nonusers regarding anthropometric data, smoking status, or nutritional intake. Male users of vitamin supplements had a lower level of overall nutritional knowledge than did nonusers, whereas no differences were found among women; the level of nutritional knowledge was, however, very low in all groups. Finally, among both sexes, no differences were found between users and nonusers regarding nutritional knowledge of vitamin intake-associated risks or benefits. The results indicate that the prevalence of vitamin supplement use is relatively modest among Portuguese health science students and is not related to a better nutritional knowledge or healthier lifestyle. (C) 2004 Elsevier Inc. All rights reserved.