Table 3.

Factors affecting log of 25 (OH) vitamin D level using multiple linear regression analysis

Variables	Coefficient	Standard error	P
Age, years	0.003	0.003	0.189
Body mass index, kg, m^2	0.002	0.005	0.608
Haemoglobin, g/dl	0.013	0.021	0.525
TSH, miU/l	-0.002	0.008	0.814
FT3, pmol/l	0.000	0.034	0.998
FT4, pmol/l	− 0.001	0.011	0.913
Case (hypothyroidism) versus controls	0.023	0.068	0.741