In the back of my mind was a thought about iron levels and I found this.
Body Cue No. 1: Cracks at the corners of your mouth.
The Deficiency: Iron, zinc, and B vitamins like niacin (B3), riboflavin (B2), and B12. "It's common if you're a vegetarian to not get enough iron, zinc, and B12," Blum says. Ditto if you're skimping on essential immunity-building protein due to dieting.
The Fix: Eat more poultry, salmon, tuna, eggs, oysters, clams, sun-dried tomatoes, Swiss chard, tahini, peanuts, and legumes like lentils. Iron absorption is enhanced by vitamin C, which also helps fight infection, so combine these foods with veggies like broccoli, red bell peppers, kale, and cauliflower.
Might be worth trying some vitamin drops.