Trace and ultra trace minerals Flashcards
What are the trace minerals?
iron, chromium, copper, fluoride, manganese, zinc
What is iron, its RDA and how much is found in body?
RDA: 8 mg per day
Only 3-4 grams found in our body and it si part of the prosthetic group - heme, which incolves haemoglobin and myoglobin and cytochromes.
75% found in haemoglobin and myoglobin and 25% found in tissues ( liver, reticuloendothelial system)
Sources: dried beans, dried fruits, eggs, fortified cereals, lvier, red meat, oysters, whole grain, salmon and tuna.
its absorption is increased by vitamin C and meat whereas decreased by vegetable fibers and black tea.
Storing and absorption of iron?
Absorbed in the upper small intestine and it binds protein: transferin for transport (30 % saturated) and ferritin for storage.
2 forms: dietary iron: ferric iron Fe+3 and reduced ferrous iron (fe2+) which is stored. It is stored in enterocytes which are refulated by the iron regulatory proteins. It can be transported to erythroblast to incorporate heme and stored in RBC. Old RBC are degraded by macrophages in order to reoxidize to Fe3+ and release in plasma.
Iron deficiency?
Anemia:
decreased energy, shortness of breath, headache, irritability, dizziness and weight loss. It is a poblem among women (10-15%) due to loss of blood in the menses being greater than the rate replaced by absorption of dietary iron. In developing countries intestinal parasite cause significant loss of blood in the faeces.
Other effects: impaired thermoregulation, immune dysfunction, GI disturbences, neurocognitive impairment in children and in pregnancy it may lead to increased risk for low birth weight, preterm delivery, perinatal mortality, infant and young child mortality and maternal mortality.
Hemochromatosis?
iron absorption disorder in which iron is accumulated in heart, liver and pancreas. This resutls in liver cirrhosis, hepatocellular carcinoma, diabetes, arthritis and heart failure. Caused by mutated HFE gene (hereditory hemochomatosis protein). Mutations to other proteins can lead to similar features.
Other iron overload conditions: RBC synthesis is abnormal, diseases requiring frequent blood transfusion and poisining from supplements ( common in children under 6)
Ultra trace minerals?
iodine, molybdenum: cofactor of 3 oxidases, selenium: 25 selenoproteins and toxic from supplements, cobalt: cobalamin.
How to measure iron deficiency?
measurments of trasnferring from iron binding glycoprotein and ferritin (iron carrier), measured in plasma, hematologic variables and the bone marrow smear.
Where and how much of iodine found in body?
15-20 mg with 80 % of it in thyroid glands. You can get it from sea water, sea food, fish and fortified salt.
Function of iodine?
it accumulates in the thyroid and forms part of the active thyroid hormones receptor. It has a variety of effects on metabolic rate, protein synthesis, and growth and development.
Deficiency of iodine?
Hypothyroidism - leads to goiter (visible enlargment of the thyroid gland) and lower metabolic rate, lethargy, dull mental apathy. Selenium is important in metabolism of thyroid homrones so a deficiency in selenium will exacerbate iodine defeciency.
