Check your ferritin
An iron deficiency is the most common nutrient deficiency. To make it simple, it means that you are losing more iron than you are getting from your food. For women, heavy periods are the most common reason for iron deficiency. Sometimes you can't get enough iron from your nutrition or iron does not absorb well. One of the best sources of iron is liver, meat, and full-grain products. A good tip is to have a bit of vitamin C on your meals, (like sweet pepper or cabbage). Vitamin C helps the iron to absorb better. On the other hand, caffeine (e.g. coffee or Coke) right after a meal can prevent or decrease the absorption of iron.
The only way to know your iron levels is to test them in the laboratory. Anemia means that your hemoglobin levels are lower than normal and it is caused by a lack of iron. However, the ferritin levels tell you how much you have so-called storage iron in your system, and it can be measured already before you develop anemia. You can ask your doctor for an iron level study in the laboratory if you suspect iron deficiency and want to know your ferritin level. Meanwhile, you can prevent having low iron levels by taking good quality supplements that absorb well in addition to having a healthy, versatile diet. Many people have noticed that iron supplements in spray or drop format absorb better than tablets. Also, a tablet combining iron with vitamin B and C might be a good way to ensure that all required nutrients are taken at the same time.