Table 2.

Comparison of vitamin D levels based on regularity and duration of the cycle

	N	Mean $\pm$ SD	t value	p-value
Irregular cycle	83	14.56 $\pm$ 8.76
Regular cycle	83	21.90 $\pm$ 6.15	-6.27	$\le$ 0.001**
Infrequent cycle	69	15.00 $\pm$ 9.17
Frequent cycle	14	12.96 $\pm$ 6.13	1.10	0.27***
Student's t test, **P $<$ 0.001 so is significant, *** P $>$ 0.05 so is not significant