It is very easy to not get enough Vitamin E. Sunflower seeds have loads of Vitamin E -- AND -- Selenium - an important nutrient for the immune system.
Bonus: sunflower seeds are one of the CHEAPEST sources of both.
I encourage everyone to use a food diary site like CronoMeter.com for 1 week. You may be surprised by what you are and are not getting in your diet.
https://www.nationalgeographic.com/premium/article/diet-seeds-nutrition-hierarchy