Table V.

Epidemiologic characteristics of alopecia areata patients and corresponding mean vitamin D levels

Epidemiologic factors		Number of AA patients	Mean vitamin D level ± SD (ng/mL)
Age		29	See note∗
Sex	Male	10	27.81 ± 8.35
	Female	19	22.63 ± 5.37
Body mass index		29	See note∗
Sun exposure	<30 min per d	16	22.13 ± 5.64
	≥ 30 min per d	13	27.22 ± 7.40
Skin phototype	III	3	23.35 ± 4.10
	IV	24	24.62 ± 7.02
	V	2	31.59 ± 1.15
Photoprotection practices (apart from sunscreen use)	Present (umbrella, caps or hats, and clothing)	22	24.98 ± 7.34
	Absent	7	22.61 ± 5.17

AA, Alopecia areata; BMI, body mass index.

^∗The stratification of age and BMI into groups was not done because both were continuous variables. Hence, the mean vitamin D level is the same as that of AA patient group. The correlation of age and BMI with vitamin D level was analyzed using the Pearson correlation.