Feeling lethargic? It might be an iron deficiency.

Between crazy morning routines, little league games after work, and piles of laundry waiting to be washed at night, who doesn’t feel fatigued from time to time? In fact, most of us get so used to being tired that we forget what having energy actually feels like.

But some fatigue might not have anything to do with your go-go-go schedule. Anemia, which can be caused by an iron deficiency, makes the body feel chronically weak and tired. You may even feel short of breath or dizzy, or you might suffer from headaches.

Iron is essential for helping the body produce the protein hemoglobin. If your red blood cells don’t have enough hemoglobin, they won’t be able to carry as much oxygen from the lungs throughout the body, according to the National Heart, Lung, and Blood Institute. Without that oxygen to fuel you, you’ll be left feeling weak and lethargic.

Men ages 19 to 50 need 8 milligrams of iron daily, and women need 18 (some iron is lost during your period). Women who are pregnant should get a whopping 27 milligrams of iron. After age 50 (or after menopausal), 8 milligrams of iron a day is adequate for everyone.

Here are the top food sources of iron to help you reach the recommended dietary allowance (RDA).

• 95% lean ground beef: 2.4 mg in 3 oz

• Chicken: 1.1 mg (dark meat) or 0.9 mg (light meat) in 3 oz

• Pork: 0.6 mg in 3 oz

• Canned salmon: 0.6 mg in 3 oz

• Fortified whole wheat flake cereal: 18 mg in ¾ cup

• Cooked spinach: 3.2 mg in ½ cup

• Wheat bran: 3 mg in ½ cup

• Lima beans: 2.1 mg in ½ cup

• Red kidney beans: 2 mg in ½ cup

• Eggs: 0.8 mg in 1 egg

Before you head off to saute some spinach and grill a chicken breast, think of adding a little citrus. It turns out, pairing iron with vitamin C helps your body absorb the iron better. Sounds like a great excuse for a mimosa, if you ask us.  (Or, you know, you could just add a hearty squeeze of lemon or a few slices of red bell pepper.)