Table 2: Vitamin D deficiency in relation to stage of COPD.

PFT stage	Total no. of patients	vitamin D (< 20 ng/ml)	Percentage	GOLD group	Total no. of patients	vitamin D (< 20 ng/ml)	Percentage
I	16	6	37.50%	A	42	14	33.33%
II	63	26	41.27%	B	23	9	39.13%
III	70	52	74.29%	C	21	10	47.62%
IV	33	27	81.82%	D	96	81	84.37%