Table 3. Effect of smokeless tobacco (ST) consumption alone or with betel nut on concentrations of plasma/serum homocysteine, folate, vitamin B12, PLP and cholesterol and blood Pb in normal healthy adults.

Variable	Concentration			p-value*
	Smokeless Tobacco Use
	Never	Alone	With betel nut
	(n = 638)	(n = 88)	(n = 146)
Homocysteine(µmol/L)	11.95±5.5	17.7±7.5	25.48±15	<0.001
Folate (ng/mL)	7.1±4.7	6.07±4.1	4.68±3.1	<0.001
Vitamin B12 (pg/mL)	456±241	406±203	391±173	0.003
PLP (nmol/L)	34.2±36.1	28±18	31.5±23	0.2
Cholesterol (mg/dL)	158±35	164±35	162±38	0.17
Blood Pb (µg/dL)	11.4±5.4	12.6±5.8	12.3±5.7	0.05

Mean±SD.

^*p-value compares the mean values among the non-users, ST users and ST along with betel nut chewers using one way ANOVA. Tukey’s HSD multiple pair-wise comparison showed that ST users (with and without betel nut) had significantly higher levels of plasma homocysteine (p<0.001) compared to non-users of ST. Regarding serum folate and serum B12 levels, the group chewing tobacco along with betel nut was found to have significantly lower levels of folate and vitamin B12 compared to the non-users group (p<0.001 and p = 0.003, respectively).