Knowledge of vitamin D and practices of vitamin D supplementation in a Scottish adult population: A cross-sectional study.

Background: Vitamin D supplementation practices (dose and frequency) are relatively unknown in the Scottish population, with no recent up-to-date data available. Reassessing current knowledge, practices, and awareness of vitamin D supplementation following a national health campaign in 2020 by Food Standards Scotland on vitamin D is warranted. Aim: This article aims to present the knowledge and awareness of vitamin D, and current vitamin D supplementation practices in adults living in Scotland. Methods: A cross-sectional study was performed between June and July 2022 using an online survey adapted from previous work on assessing knowledge of vitamin D in adults. Participants aged 18+, living in Scotland for ≥6 months were eligible to participate. Scores for knowledge were calculated as a percentage. Univariate associations between demographic and supplement use were established by χ²-test and logistic regression performed to predict factors associated with daily vitamin D intake. Results: Four hundred and three participants (72.7% female), mean age 36.4 (±14.2 years), completed the study. Awareness of vitamin D was very high (99.5%) but the mean overall knowledge score was poor (31.4 ± 15.3%), with those with a university degree more likely to have knowledge scores at/above the mean compared with those with lower levels of education, χ²(1, N = 393) 10.7, p = 0.001, odds ratio (OR) = 2.1 (95% confidence interval (CI) 1.7-2.7). Finally, 64.3% took vitamin D supplements, of which 37.5% took them daily during winter months, with only 7.4% taking the recommended daily dose. Conclusion: The current study highlights the need to improve both knowledge of vitamin D and practices of vitamin D supplementation during the autumn and winter months in Scotland.