Comparing measured calcium and vitamin D intakes with perceptions of intake in Canadian young adults: insights for designing osteoporosis prevention education.

Objective: To identify the relationship between perceptions of Ca and vitamin D consumption and actual intakes to inform the design of osteoporosis prevention education.

Design: An FFQ was used to approximate usual monthly Ca and vitamin D intakes among a group of young Canadians. Qualitative interviews and a food card pile sort activity explored individuals' perceptions of nutrient intakes. The FFQ was used to assess nutrient adequacy for individual participants and the qualitative interviews and pile sort were analysed using thematic content analysis.

Setting: Hamilton, Canada.

Subjects: Sixty participants aged 17-30 years, representing varying levels of educational attainment.

Results: Seventy-eight per cent of young adults who consumed inadequate vitamin D perceived their intake as adequate, compared with 57 % for Ca. Thematic analysis revealed three major themes that contributed to young adults' understandings of intake: belief their diet was correct, absence of symptoms and confusion over nutrient sources.

Conclusions: The majority of participants perceived themselves as consuming adequate amounts of Ca and vitamin D, when they were actually consuming inadequate amounts according to FFQ findings. These perceptions were related to low engagement in prevention activities. Prevention education must motivate young adults to question the adequacy of their micronutrient intakes and design tailored programmes that are geared to a young adult audience.