Iron...How do I Know if I'm Low?

I've had several women in the last few months come to me with complaints of low iron. Many of them didn't know their iron was low until they did a blood test. In America, 20% of women are iron deficient. 

What are the symptoms of low iron?
1- Fatigue
2- Pale skin
3- Dizziness, lightheaded, weakness
4- Fast heart rate, chest pain
5- Headaches
6- Stomach pain
7- Joint pain
8-Craving to eat items that aren't food- ice, dirt, or clay

Raising iron levels through supplementation: 
1- Always get a blood test before starting supplementing
2- Ferrous gluconate form is gentle on the bowels
3- Take vitamin C with iron supplement to increase absorption

Raising iron levels through diet: 
1- Beef
2- Liver
3- Turkey
4- Chicken
6- Fish
7- Spinach
8- Pumpkin and sunflower seeds
9-Firm tofu
10- Beans and lentils