When a person has a low ferritin level then it usually indicates that the person who has the low ferritin level also has an iron deficiency.
So you need to get more iron in your body to increase your ferritin levels.
Some foods you can eat to increase your ferritin levels and iron intake are lean red meats and chicken and fish as well.
Those foods can help increase your iron intake which also helps to raise and increase your ferritin levels to the optimal levels.
Also eating foods that are rich in Vitamin C can help with the bodies absorb of the iron that you do intake so that your body has an increase in iron and ferritin levels.
Ferritin is the primary form of iron stored inside of the body's cells and is very important to your health and if you're constantly feeling fatigued then your Ferritin levels are likely low.
You can get your ferritin levels tested through a blood test and you might be given medication as well to help increase your ferritin levels.