Table 2.

Mean serum levels of vitamin D3 (nmol/L) among patients with periodontitis vs. healthy controls.

Groups	N	Mean	Mean Diff.	p-Value
		(SD)	(95% CI)
Overall
o Periodontitis	50	31.34 (5.62)	8.3	<0.001 !
o Healthy controls	50	39.64 (8.77)	(5.37 to 11.22)
Male
o Periodontitis	25	31.64 (5.67)	8.23	0.001 !
o Healthy controls	24	39.88 (9.69)	(3.61 to 12.85)
Female
o Periodontitis	25	31.04 (5.67)	8.38
o Healthy controls	26	39.42 (7.99)	(4.46 to 12.29)	<0.001 !
Age < 50 years
o Periodontitis	22	32.50 (5.58)	7.63	0.002 !
o Healthy controls	22	40.14 (9.39)	(2.93 to 12.33)
Age > 50 years
o Periodontitis	28	30.43 (5.58)	8.82	<0.001 !
o Healthy controls	28	39.25 (8.38)	(5.00 to 12.63)

Vitamin D3 levels were measured in nmol/L; !—p-values for equal variance not assumed in multiple independent-samples t-tests with Bonferroni adjusted level of significance alpha = 0.01.