I is for Iron

NUTRITION TIP THURSDAY

I | IRON

by Lindsey Herr

What is Iron?

Iron is a natural mineral. It is found in many of the foods we eat (naturally and fortified) or available as a supplement. Iron is an essential component of hemoglobin and myoglobin. It is not made in the body and must be consumed in our diets. When iron stores are exhausted, iron deficiency occurs and further decreases may result in iron deficiency anemia.

Functions:

  • Hemoglobin is a protein in our blood that transports oxygen to the lungs and rest of the body

  • Myoglobin is in our muscles to accept and release oxygen  

  • Supports metabolism

  • Growth, development, normal cellular functioning

  • Synthesis of some hormones and connective tissue

Heme Vs. Non-Heme Iron:

Plants and iron-fortified foods contain non-heme iron only. Meat, seafood, and poultry contain both heme and non-heme iron. Because of its structure, non-heme iron must change chemical forms before it can be used in our own blood system.  This makes heme iron the easier of the two to digest. It is not unsafe for vegetarians to not eat meat. However, often, vegetarians have low iron levels in their blood. As a vegetarian, you must be sure to consume extra iron-rich foods to keep your serum iron levels up to where they should be!

Lab Values Pertaining to Iron Levels in the Blood:

Serum Iron

Iron is a measure of the iron circulating in the blood. The level is determined by the absorption from the intestine, storage in the intestine, liver, spleen, and bone marrow, rate of breakdown or loss of hemoglobin, and the rate of production of new hemoglobin.

TiBC

Total iron binding capacity is a measure of all of the proteins in the blood that are available to bind with iron. Transferrin in the primary iron-binding protein and as a result TIBC is a good indirect measure of transferrin. The body regulates transferrin based on the level of iron in the body. If iron levels are low the body will produce more transferrin.

Ferritin

Ferritin is a blood cell protein that holds and stores about 25% of your body’s iron. When a doctor measures your ferritin they are able to tell your long-term iron capacity and how well your body stores iron. When iron intake is consistently low, stored iron can become depleted and eventually hemoglobin levels can drop (iron deficiency anemia).

UIBC

Unsaturated iron binding capacity is a measure of the portion of transferrin, or the protein that binds iron for transport, that has not yet been saturated. It is a reflection of transferrin levels.

Iron-Rich Foods:

*Be sure to eat a variety of these!*

  • Lean beef
  • Veal
  • Pork
  • Lamb
  • Chicken
  • Turkey
  • Fish
  • Mussels
  • Shellfish
  • Leafy Greens
  • Tofu
  • Broccoli
  • Sweet Peas
  • Brussels Sprouts
  • Kale
  • Bean Sprouts
  • Tomatoes
  • Lima Beans
  • Potatoes
  • Green Beans
  • Corn
  • Beets
  • Cabbage

Bonus Tip:

Consuming foods with Vitamin C with non-heme iron will help with absorption!


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