Complementarity in dietary supplements and foods: are supplement users vegetable eaters?

Abstract

Background: The consumption of fruits, vegetables, and dietary supplements correlate. Most previous studies have aimed to identify the determinants of supplement uses or the distinct features of supplement users; this literature lacks a discussion on dietary supplement consumption as a predictor of fruit and vegetable consumption. Objective: This study examines how dietary supplement consumption correlates with fruit and vegetable consumption by combining scanner data and surveys of Korean household grocery shopping. Methods: Propensity score matching (PSM) is used to identify the relationship between dietary supplement consumption and fruit and vegetable consumption in a household. A logit regression using supplement consumption as the dependent variable is used. Then, the supplement takers (the treatment group) are matched with non-takers (the control group) based on the propensity scores estimated in the logit regression. The fruit and vegetable consumption levels of the groups are then compared. Results: We found that dietary supplement use is associated with higher fruit and vegetable consumption. This supports the health consciousness hypothesis based on attention bias, availability heuristics, the focusing effect, and the consumption episode effect. It rejects the health substitute hypothesis based on economic substitutes and mental accounting. Conclusions: Future research on the health benefits of dietary supplements should address the complementary consumption of fruits/vegetables and their health benefits to avoid misstating the health effects of supplements.

Habits and beliefs related to food supplements: Results of a survey among Italian students of different education fields and levels

“…Most food supplement users took multivitamins, and many took a variety of products. The consumption of vitamins and minerals, regardless of the intake from food alone, is a common attitude in different age groups, particularly in individuals who have a significant concern for their overall health [ 20 ] and in those from families with a high socioeconomic level [ 21 , 22 ].…”

Food and nutrient intake in dietary supplement users: a nationwide school-based study in Japan

“…The finding that dietary supplement users consumed less healthy diets than non-users may be explained by the ‘compensation hypothesis’ ( 42 , 44 – 46 ) , which suggests that individuals use dietary supplements to compensate for an unhealthy diet. The use of dietary supplements by children may reflect their guardians’ belief that dietary supplements such as multivitamins are a good substitute for fruits and vegetables, based on the rich vitamin and mineral content of these foods.…”

Association between neighbourhood deprivation, fetal growth, small-for-gestational age and preterm birth: a population-based prospective cohort study

“…We chose not to adjust for nutritional factors other than alcohol intake and folic acid supplement use since alcohol intake and folic acid supplement use are strongly correlated with other lifestyle and nutritional habits. 30 31 Third, we adjusted the analyses for individual factors to isolate a neighbourhood-specific effect. However, we cannot rule out the presence of residual confounding caused by other individual factors that are strongly associated with fetal growth.…”