Question: how to boost white blood cell levels?
Answer: Citrus fruits. Most people turn to vitamin C after they've caught a cold. ... 
Red bell peppers. If you think citrus fruits have the most vitamin C of any fruit or vegetable, think again. ... 
Broccoli. ... 
Garlic. ... 
Ginger. ... 
Spinach. ... 
Yogurt. ... 
Almonds.