Dr. Christy Alexon returns to the show to discuss the importance of vitamin supplementation for the hard-training individual. She focuses on three key vitamins and supplements -- Vitamin C, D, and probiotics for the gut -- which are often overlooked by otherwise macro-compliant lifters. Taking vitamins or probiotics doesn't just mean popping a pill, however, and Dr. Alexon recommends supplementing with natural foods first before turning to pharmacy-bought, OTC supplements.