For a review of previous lessons, go to www.milkandhoneyhealthfoods.com/archive12.html  for a review of lessons one through three, www.milkandhoneyhealthfoods.com/archieve13.html for a review of lessons four through six,   www.milkandhoneyhealthfoods.com/archive14.html  for lesson seven through nine,
www.milkandhoneyhealthfoods.com/archieve15.html for lesson ten through twelve.

www.milkandhoneyhealthfoods.com/archieve16.html for lesson thirteen through sixteen

NUTRITION 101: LESSON SIXTEEN

 

       In our last Newsletter, we discussed the micro mineral zinc. This month we will look at the trace mineral iron.  Remember, micro minerals are minerals which the body needs in less than 100 milligrams per day. Such minerals are often needed in just micrograms per day.  There are 1000 micrograms to one milligram.      

IRON:

        Iron is an alkaline forming micro mineral. The average human body contains a total of 4,000 mg (4 grams) of iron.  Irons primarily role in nutrition is as a carrier of oxygen in the body.  It does this as part of the blood protein hemoglobin and the similar oxygen carrying protein called myoglobin which is found in the muscles. Almost two-thirds of iron in the body is found in hemoglobin.  Iron also aids in immune function, cognitive development, temperature regulation, energy metabolism, and work performance. About 90% of the iron in our body is conserved and reused every day. The rest is excreted. Men are able to naturally store more iron than women. In order to maintain iron balance in the body, dietary iron must supply enough iron to meet the 10% gap that our body has excreted or else deficiency will result.  A deficiency of iron limits oxygen delivery to cells, resulting in fatigue, poor work performance, and decreased immunity

        Iron is mainly absorbed in the duodenum and upper jejunum of the small intestine. . A transporter protein called Divalent Metal Transporter facilitates transfer of iron across the intestinal epithelial cells. Absorbed iron is bound in the bloodstream by the glycoprotein named transferrin. About 10 to 20% of absorbed iron goes into storage and is used as needed

TYPES AND SOURCES OF IRON:

       Dietary sources of iron are found in two forms.  Heme iron and nonheme iron. Heme sources are provided by animal tissues (meats) and are readily absorbed. Approximately 40% of iron found in meat is heme, with the best sources being liver, seafood, fish, lean meat, and poultry. Nonheme iron is provided by plant sources and elemental components of animal tissues. It is less efficiently absorbed, and its amount of absorption depends upon the body’s needs.  If the body is low in iron, more nonheme iron will be absorbed. If the body is high in iron less will be absorbed.  Nonheme sources that are high in iron include cooked spinach, beans, eggs, nuts, fortified breads, cereals, and flours. The nonheme form of iron is the form added to iron-enriched and iron-fortified foods.      Meat proteins and vitamin C will improve the absorption of nonheme iron. Tannins as found in tea, the mineral calcium, chemical compounds called polyphenols and phytates found in legumes and whole grains can decrease absorption of nonheme iron.

 IRON AND BREAST FEEDING:

       Iron in human breast milk is well absorbed by infants. It is estimated that infants can use greater than 50% of the iron in breast milk as compared to less than 12% of the iron in infant formula. The amount of iron in cow's milk is low, and infants poorly absorb it. Feeding cow's milk to infants also may result in gastrointestinal bleeding. For these reasons, cow's milk should not be fed to infants until they are at least 1 year old. The American Academy of Pediatrics (AAP) recommends that infants be exclusively breast fed for the first six months of life.

IRON DEFICIENCY:

       The World Health Organization considers iron deficiency the number one nutritional disorder in the world. As many as 80% of the world's population may be iron deficient, while 30% may have iron deficiency anemia. Iron deficiency develops gradually and usually begins with a negative iron balance, when iron intake does not meet the daily need for dietary iron. This negative balance initially depletes the storage form of iron while the blood hemoglobin level, a marker of iron status, remains normal. Iron deficiency anemia is an advanced stage of iron depletion. It occurs when storage sites of iron are deficient and blood levels of iron cannot meet daily needs. Blood hemoglobin levels are below normal with iron deficiency anemia.  Iron deficiency is not a problem for most Americans because of our high consumption of animal products.

DAILY REQUIREMENTS:

        Most Americans meet the recommended daily allowance (RDA) of iron for men at 10 mg per day and the RDA for women at 15 mg per day.  During Pregnancy, women require a total of 60 mg of iron per day.   The optimal daily allowance of iron for adults can range anywhere from zero to forty mg per day depending on the level of iron storage in the body and the bodies needs based on life style.  A simple self-test can be used to indicate adequate/deficient iron status.  Place one of your hands flat on a table (palm down) and press firmly down on one fingernail to force all the blood out of the underlying nail-bed.  When you remove pressure, watch to see if rosy pink color returns immediately.  If there is no color change, this may indicate an Iron deficiency.

VEGETARIANISM AND IRON:

       Vegetarian diets may not meet recommended levels of daily iron intake. Vegetarians who exclude all animal products from their diet may need almost twice as much dietary iron each day as non-vegetarians because of the lower intestinal absorption of nonheme iron in plant foods. Vegetarians need to be aware of possible iron deficiency and should consider consuming adequate vitamin C to  improve the absorption of nonheme iron.

IRON TOXICITY:

       There is risk for iron toxicity because very little iron is excreted from the body. Thus, iron can accumulate in body tissues and organs when normal storage sites are full. Some research indicates that excess iron in the body may be a contributing dynamic in the development of some types of cardiovascular disease and certain cancers. Excess Iron has been associated with prostate and colon cancer.  Excess iron over and above body requirements can create free radical damage to tissues.  Many supplement companies have come out with iron free multiples for those desiring to limit their iron intake.  Older adult men and post-menopausal women may want to use such multiples. 

IRON SUPPLEMENTATION:

       Iron supplementation may be necessary when iron deficiency s indicated.  Individuals who may be in need of iron supplementation are vegetarians, those that exercise in excess, women that bleed excessively during menstruation and women that are pregnant.  Adult men and postmenopausal women should not take iron supplements without an appropriate medical evaluation for iron deficiency. A number of iron supplements are available, and different forms provide different proportions of elemental iron. For example, ferrous sulfate heptahydrate is 22% elemental iron; ferrous sulfate (monohydrate) is 33% elemental iron, ferrous gluconate is 12% elemental iron and ferrous fumarate is 33% elemental iron. Elemental iron is the amount of actual iron in the supplement.  When taking iron supplements it is best to take food based or well chelated iron for best utilization by the body.  Chelation is the process whereby minerals are attached to various carrying agents such as various acids common to our body.