It's just the oil in the vitamin E that's causing a bit of loose poop. Make sure your chick is eating and drinking well.
For treatment of Wry Neck, 400IU Vitamin E and 1/4 tablet B-Complex is the standard for all ages. A bit of egg is sufficient for Selenium which helps with the Uptake of E...
"Wry Neck", "Crookneck", etc., is a Neurological symptom. Common causes are disease like Marek's, head/neck trauma, vitamin/nutritional deficiency and/or sometimes genetics.
Silkies seem to be more prone to Neurological symptoms and may need to be offered supportive vitamin therapy from time...