Table 1

Topic	Urban/rural	Yes (%)	No (%)	OR (CI)	P value
Do you think vitamin and minerals are essential for health?	Urban	1872 (100)	0 (0)	-	0.8
Do you think vitamin and minerals are essential for health?	Rural	1120 (100)	0 (0)	-	0.8
Do you think calcium is an important micronutrient?	Urban	1704 (91.0)	168 (9.0)	1	0.49
Do you think calcium is an important micronutrient?	Rural	1011 (90.3)	109 (9.7)	0.91 (0.71-1.18)	0.49
Do you think vitamin D is essential for human health?	Urban	1677 (89.6)	195 (10.4)	1	0.001
Do you think vitamin D is essential for human health?	Rural	958 (85.5)	162 (14.5)	0.69 (0.55-0.86)	0.001
Sunlight may produce vitamin D: do you agree?	Urban	1457 (77.8)	415 (22.2)	1	0.036
Sunlight may produce vitamin D: do you agree?	Rural	834 (74.5)	286 (25.5)	0.83 (0.7-0.99)	0.036
Are you familiar with the term "Osteoporosis"?	Urban	1146 (61.2)	726 (38.8)	1	0.0056
Are you familiar with the term "Osteoporosis"?	Rural	628 (56.1)	492 (43.9)	0.81 (0.7-0.94)	0.0056
Name of at least one calcium containing food name^‡	Urban	758 (40.5)	1114 (59.5)	1	0.5805
Name of at least one calcium containing food name^‡	Rural	465 (41.5)	655 (58.5)	1.04 (0.9-1.21)	0.5805
Name of at least one vitamin D containing food name^‡	Urban	740 (39.5)	1132 (60.5)	1	0.39
Name of at least one vitamin D containing food name^‡	Rural	425 (38.0)	695 (62.0)	0.94 (0.08-1.09)	0.39
Have you ever been prescribed a calcium and/or vitamin D by your physician? ¶	Urban	925 (49.4)	947 (50.6)	1	<0.0001
	Rural	313 (28.0)	807 (72.0)	0.4 (0.34-0.47)	<0.0001

^‡The interviewers instructed the students not to mention milk or sunlight as a source as they are already mentioned in the questionnaire. In these cases we have not considered whether the food is available in Bangladesh or not
¶ Students were provided with some commercially available brand names of calcium and/or vitamin D supplements. The names were given for their better understanding. The authors have no financial or personal or otherwise any short of relationship with the manufacturers of the brands. The brand names are not mentioned in the manuscript Abbreviation: OR: Odd Ratio, CI: Confidence Interval

Table 1: Familiarity with the basics of calcium and vitamin D.