Table 5.

Effect of 25(OH)D sufficient versus insufficient on the presence of CTD, comorbid OCD, and ADHD

Dependent variablea	OR	95% CI	p
CTD	3.05	1.39–6.71	0.01*
Tic onset	2.00	0.70–5.72	0.19
CTD comorbid OCD	1.15	0.63–2.11	0.65
CTD comorbid ADHD	0.54	0.29–1.00	0.05*

^aThe dependent variable is the presence of CTD, tic onset, OCD, or ADHD and the primary predictor variable is a binary measure of 25(OH)D insufficiency/sufficiency, where adjusted 25(OH)D insufficiency (≤ 20 ng/ml) = 0 and sufficiency (> 20 ng/ml) = 1. Thus, the odds ratio is calculated for those sufficient as compared to insufficient, i.e., the odds of having CTD were higher (OR = 3.05) in those with sufficient 25(OH)D compared to those with insufficient levels, whereas the odds of having ADHD were lower (OR = 0.54) in those with sufficient 25(OH)D compared to those with insufficient 25(OH)D. Sex, age,and comorbidity, other than that being tested, were also entered as covariates

CTD chronic tic disorder, OCD obsessive–compulsive disorder, ADHD attention-deficit hyperactivity disorder)

*The significant difference with p < 0.05