A lymphatic organ that helps develop the immune system is the thymus gland.
Women should have 18 mg of iron a day unless pregnant or breast feeding.
Hope I helped
I believe the answer is: Eat a well-balanced diet to increase energy and immunity
Even though physical activities improve both our energy and immunity in the long run, they are not as significant as maintaining well balanced diet in your life.
You need to make sure that you get your nutrients from various source of non-processed food in order to fulfill both your macronutrients and micronutrients.
