Table 4.

Habit-tic deformity studies

Study	Design	Therapy	Dosage	Sample size	Patient demographics (age/sex)	Nail involvement	Outcomes
Gloster and Kindred (2005) [46]	Case series	Oral multivitamin (vitamin C, B9, B7, zinc, keratin, para-aminobenzoic acid, lemon bioflavanoid)	1 multivitamin/day	2 patients	33/F; 39/M	Fingernails	Case 1: Near complete resolution of left thumbnail dystrophy (at baseline had multiple transverse ridges of the nail plate) after 5 months. The patient continued the multivitamin for 1 year and retained normal nails thereafter; case 2: Complete resolution of bilateral thumbnail dystrophy (at baseline had transverse ridges of the nail plates with central depression) after 4 months. Recurrence occurred within 6 months after discontinuing. The patient then took biotin 2.5 mg/day for 6 months without improvement. He subsequently began taking multivitamin again with resolution.