Factors associated with the intention to use vitamin D supplements: Quantitative study among a sample of elderly people in a medium-sized town in theNetherlands

The objective of this study was to assess which factors are related to the intention of elderly people to use vitamin D supplements. A questionnaire t hat was based on several theories. feedback of experts. and personal interv iews with members of the target group was distributed among a random sample of 497 elderly people in a medium-sized town in the Netherlands (response 46%). Variables measured included perceived susceptibility, severity and co ntrol with respect to developing a vitamin D deficiency or getting a bone f racture, and beliefs, perceived social norms, modeling, self-efficacy. and intention with respect to the use of vitamin D supplements. Univariate anal ysts of variance, chi-square tests, stepwise multiple regression, and stepw ise logistic regression analysis were performed. Respondents reporting a hi gh intention had more positive attitudes and normative beliefs, higher self -efficacy expectations with respect to using vitamin D supplements, and mor e often used other supplements than respondents with a low intention. Subje cts who already used vitamin D supplements were more often female and alrea dy familiar with the advice and had more positive attitudes and normative b eliefs than nonusers. It was concluded that many elderly people have high i ntentions to start using vitamin D supplements as soon as they hear about t he advice. A health promotion campaign to promote the use of vitamin D supp lements should aim at making elderly people familiar with the Health Counci l of the Netherlands' advice. Furthermore, the campaign should place emphas is on changing attitudes, perceived social norms, and self-efficacy expecta tions toward vitamin D supplement use.