I take collagen powder, zinc, multivitamins, omega3, magnesium, turmeric, coq10, and some skin vitamins. I take them during my feeding window, with meals or snacks. The only vitamin I take while fasting is magnesium bc it helps me sleep and doesn’t irritate my stomach. the only supplement I take fasted is LiquidIV or similar products. I do a 16:8 fast daily, and this is what works for me. I’m not sure how vitamins factor in with extended fasts, but whenever I take vitamins on an empty stomach, I throw them up.