IRON
General Description:
- for decades iron has been known as the ''king of minerals''
- calcium has now replaced it in the limelight
- there are three forms of iron supplementation: 1) the ferrous family, 2) the ferric
family, and 3) reduced iron
- the differences in absorption between the three seems to be insignificant
- iron sulphate or oxide are useless compared with iron as ferrous fumarate or iron picolinate
- principle synergists to iron are folic acid, B5, C, E, B12, and Zn
Actions:
- iron is also a crucial part of a variety of different enzymes
- some Fe is converted into myoglobin, a hemoglobin-like substance found in the muscle
fibers
- myoglobin is our ''iron bank'' storing iron for future use
- the only organism that can survive without iron is the lactic acid bacteria (''friendly
bacteria'')
- when a human baby is born, its GI tract is sterile, that is, it contains zero bacteria
- it also contains zero iron and therefore the only bacteria that can grow there are the
lactic acid bacteria, which start infiltrating the gut within minutes of birth
- lactic acid bacteria are necessary for the digestion of mother's milk
- Nature allows only lactic acid bacteria to grow in the newborn gut in order to protect
it from harmful bacteria that could otherwise multiply and kill the baby
- all bacteria grow greedily in the presence of iron
- mother's milk, far and away the best food for babies, contains virtually no iron
- most physicians seem to be unaware of the fact that infants do not need iron
- a human baby is born with a reserve supply of iron in its tissues of approximately 75
mg/kg of bodyweight = twice the level of iron found in healthy athletes
- infants can grow healthy and normal for one year without any external source of iron
- Nature designed it that way to allow the immune system to develop before the onslaught
of bacteria that occurs once the baby is weaned onto iron-containing solid foods
- excess iron in the body allows infection to flourish and a lot of disease in America
can be attributed directly to the overuse of iron
Blood building:
- erythrocytes, or red blood cells that carry oxygen, make up 35-50% of the blood
- the rest is plasma fluid and a few white blood cells
- proportion of the blood made of RBCs is measured by the hematocrit
- a hematocrit of 50 provides 25% more RBCs than a hematocrit of 40
- Fe is a vital component of hemoglobin which has the life-sustaining responsibilty of
picking up oxygen in the lungs and transporting it through the entire body
- each RBC is 25-35% hemoglobin and the greater the hemoglobin/RBC, the greater the amount
of oxygen the body can use
- a hemoglobin level of less than 13 g./dl. in males and less than 12 g./dl. in females
is an identifying sign of iron deficiency anemia
- so is a serum Fe level of less than 40 mcg./dl.
- however neither test gives much infor on Fe status because Fe stores can be virtually
exhausted before hemoglobin or serum Fe register at any abnormal level
- a hemoglobin test is useful to show how much of your Fe is getting converted into hemoglobin
- in conjunction with hematocrit and RBC count it is also useful to show how much oxygen
carrying capacity you have, but it is useless for determining Fe store
- hematopoietic (blood-building) nutrients that work in synergy with Fe are folate, Zn,
B12, B5, and vitamins C, and E
- erythropoiesis is the making of RBCs
- inadequate folate intake reduces RBC formation
- the average intake of folate in sedentary people has declined to 200 mcg. and thus the
RDA has been lowered to 200 mcg. (half the value it was 20 years ago)
- folate status effects iron status and vice versa
- Zn is required for increased production of RBCs, for increased free fatty acid metabolism
during exercise, for replacement of dermal losses of Zn during sweating, and for the interactions
of Zn and Fe metabolism
- erythropoiesis also requires B12 which is also essential for folate metabolism
- B5 plays a role in the formation of the heme portion of hemoglobin
- B5 deficiency impairs B12 absorption, lowering tissue levels of that nutrient
- vitamin C deficiency by itself produces anemia, as can E deficiency, no matter how much
Fe you have
- C protects folate from oxidation
- E is important in combating hemolysis, and a deficiency causes increased hemolysis because
it leaves RBCs more fragile and they are then easily damaged
- adequate E is also essential for normal metabolism of B12 and Zn
Deficiency:
- sedentary males use approximately 1.0 mg. of iron/day and sedentary females use approximately
1.5 mg. of iron/day
- the body may absorb more of a mineral from some foods than from others
- interfering factors may prevent the body from absorbing nutrients in the food, for example,
phytates, dietary fiber, EDTA in the case of iron, and coffee and tea.
- the greatest influence on iron absorption seems to be iron itself
- the best absorbed iron is termed heme iron and is found in flesh foods
- iron in non-flesh foods is not as well absorbed and is termed nonheme iron
- nonheme iron cannot be absorbed unless it is in a soluble form ie. dissoved in water
etc., which is where stomach acid and nutritional factors, such as vitamin C, can lend
a hand
- vitamin C combines with iron to make a partnership that is then absorbed
- heme iron is more readily absorbed (10% bioavailable) but while it wins for quality
nonheme iron (1% bioavailable) wins for quantity and therefore it too plays a large role
in iron contribution
- although it is commonly believed that vegetarians have a higher incidence of iron deficiency
than meat eaters this is not always the case
- the body absorbs less iron when its stores are good and absorption rises when stores
are low
- men absorb approximately 15% of the heme iron in food while women absorb 23-35% depending
on iron stores
- many heme-rich foods are also high in fat and are therefore not the best choices for
iron
- iron deficiency exists when the body's stores are inadequate, but anemia does not develop
until iron stores are depleted
- about 1/3 of the body's iron is stored as ferritin and hemosiderin in the bone marrow
and the liver
- a test of blood ferritin can diagnose iron deficiency in it's preanemic state
- blood ferritin reflects the amount of stored iron, so low levels indicate poor iron
stores
- the amount of iron in the blood (serum iron) and the percentage of iron bound to a substance
called transferrin (a protein) also drop too low in cases of anemia
- as excessive iron accumulates, however, transferrin is then able to bind an unusually
large amount of iron, termed the iron-binding capacity or TIBC
- there are also two other familiar lab tests for iron called the blood hemoglobin and
the hematocrit
- some people actually test positive for anemia on these tests may actually be experiencing
iron overload, but the problem is that they are not getting enough iron into the hemoglobin
and instead the excess iron is being stored elsewhere
- a simple way to distinguish iron-deficiency anemia and iron overload is a blood iron
level (low in anemia but not in overload)
- symptoms of iron deficiency anemia include: coldness and/or tingling of hands and feet,
craving for nonfoods such as ice or dirt, irritability, overwhelming fatigue and weakness,
sensation of rapid or fluttering heartbeat, shortness of breath upon exertion, and paleness
of the mucous membranes such as the eyelids
- infants iron stores are usually large enough to last them almost a year while they are
being breastfed and they do not require supplemental iron
- when iron is supplemented their bacterial flora is disrupted and pathogenic bacteria,
which use iron for reproduction, overgrowth and cause them many problems involving immunity
(eg. recurrent infection)
- milk (including breast milk) is a poor source of iron, but this is beneficial for the
baby to limit the iron intake until solid foods are introduced at the preferrable age of
one year
- during growth spurts in childhood and adolescence there is an increased need for iron
to fill expandin stores
- those women who bleed heavily, diet regularily, or suffer from frequent infections may
be at risk of iron deficiency
- the later stages of pregnancy are when the mother is most likely to suffer from a nutritional
deficiency so need to supplement but not with inorganic iron
- iron is lost in most body secretions, including sweat (athletes)
- in runners, food passes through the digestive tract much faster and so not as much iron
may be absorbed from food
- also a lot of iron is lost in sweat as in every liter of sweat there is approx. 0.5
mg. Fe
- compression hemolysis, crushing of blood cells by intense muscular contraction, is a
potent source of iron loss in athletes
- other sources of hemolysis and therefore Fe loss include heavy training, GI bleeding,
acidosis, and peroxidation of cellular membranes by free radicals
- calcium, fiber, and antacids can inhibit iron absorption
Interactions and Toxicity:
- excess Fe is difficult for the body to excrete
- the side effects of iron supplements include: diarrhea, stomach pain, constipation (the
most common one), headache, heartburn, loss of appetite, gas, and vomiting
- iron supplements are best absorbed on an empty stomach in the presence of vitamin C
- Ca/Mg supplements may reduce the availability of iron if taken at the same time
- tea, even worse than coffee, inhibits the absorption of iron
- iron supplements should not be used if you suffer from a peptic ulcer, ulcerative colitis,
diseases of the liver or pancreas, alcoholism, or any other condition where iron overload
may occur.
- signs of iron overload: abdominal and joint pain, weight loss, bronze coloring of the
skin, fatigue or loss of libido, symptoms of diabetes, such as excessive thirst and urination,
hunger, and frequent yeast infections in women
- iron overload may cause an enlarged spleen, damage to the heart and joints, loss of
body hair, abnormal skin pigmentation, and decreased testicle size in males
- iron overload eventually damages the liver, but in some cases, liver damage can lead
to iron overload
- IHC is a rare genetic disorder that interferes with the body's iron thermostat and causes
excess iron to be absorbed and stored
- iron was reported to provoke extreme sensitivity to sunlight in women with EPP (erythropoietic
protoporphyria)
- excess zinc interferes with iron metabolism
Sources:
- beer brewed in iron pots can be a very high source of iron and it is suspected that
alcohol itself increases iron absorption
- heme iron in flesh foods
- nonheme iron in non-flesh foods