LAUSR

Abstract This study aimed at determining the applicability planned-behaviour theory to predict the consumption of pearl vitamin D3 (1000 IU) among pregnant women in Iran in 2020. The participants of the present study were 200 pregnant women who were selected through random cluster sampling. In addition, data collection was done through the use of questionnaire and the proceeding analyses including correlation and linear regression were conducted using SPSS (version 20) (SPSS Inc., Chicago, IL) statistical software package. The findings showed that all three structure attitudes (r = 0.69, p<.001), subjective norms (r = 0.58, p<.001) and perceived behavioural control (PBC) (r = 0.52, p<.001) had significant correlations with consumption. Among the variables entered into the regression model, attitude, subjective norms and PBC were able to predict a total of 65% of pearl vitamin D3 (1000 IU) consumption variance among participants (F = 60.75, R = 0.66, R 2=0.65). According to the findings, TPB and its constructs were used to predict pearl vitamin D3 consumption in pregnant women in Iran. This outcome indicates that efforts to promote behavioural intentions through targeting subjective norms, attitude and PBC may promote pearl vitamin D3 consumption. Impact Statement What is already known on this subject? The results of this study showed predictors of pearl vitamin D3 consumption in pregnant women based on the theory of planned behaviour (TPB). Women receive adequate and proper knowledge, along with a positive attitude towards taking pearl vitamin D3, and feel that taking pearl vitamin D3 is at their discretion in terms of environmental factors (facilities and barriers), increases intend to use pearl vitamin D3. What do the results of this study add? The results of this study also showed that the amount of pearl vitamin D3 intake during pregnancy increased by pregnant women and decreased risk of foetal growth retardation, low birth weight, decreased risk of respiratory infections in infants, decreased asthma and eczema in infants. What are the implications of these findings for clinical practice and/or further research? The study showed the importance of the role of education based on TPB in consumption promoting pearl vitamin D3.