Nutrition exam 3Hematopoietic System- basically blood and bone marrow, but it could include the spleen and lymph. FOCUS: is on production of red blood cells, also clotting system (platelet cells and clotting factors) Iron: - this mineral is a key component of hemoglobin, which carries oxygen in the red blood cells. - It is also a key factor in energy metabolism and detoxification.- Two levels of deficiency: first thing that happens is deficiency, later is anemia. The anemia results in a lower production of hemoglobin and a smaller red blood cell count ( microcytic anemia). This anemia is fairly unique, it is not megaloblastic anemia which is the lack of vitamin B12 and folate. Pernicious anemia is lack of intrinsic factor which is needed for B12 absorption. - Women are at greatest risk for anemia , especially those who are menstruating- young menstruating women. Athletes also at risk.- Source: best source is meat- Iron absorption is increased by need- wine, tea decreases absorption while vitamin C - And excess of iron can be common in men and some cultures. May be related to cancer and CVD due to its ability to act as an oxidant. May end up looking like a disease- hemochromatosis, where the liver (and other organs) accumulate iron. Zinc:- Only place where we discuss zinc, except as an antioxidant enzyme- Key is that zinc is an important mineral. - Also important for immune function and energy metabolism- People that eat enough protein probably get enough zincCopper:- Important for metabolism of iron but too much can decrease zinc absorption. - A deficiency looks like an iron deficiency (microcytic anemia)Folate:- Used by the body for DNA synthesis - Deficiency: lack of folate results in lack of cells division, Therefore the precursors of red blood cells don’t divide well and the red blood cells get very big (megaloblastic anemia) They get fat because they can’t divide. - Folate is needed during pregnancy, important in prevention of neural tube damage in newborns. - Groups at risk: first problems were identified with pregnant women,- Sources: folate is named from foliage(plants). Therefore someone who eats a lot of plantsis usually not at risk. Apple has the current RDA of folate. Foods especially flour are nowenriched with folate.Vitamin B12:- Main function is DNA synthesis (like folate, they are very closely related and an excess in folate can hide a B12 deficiency---VERY BAD) - It is the largest vitamin and needs special absorption mechanisms (intrinsic factor) - Deficiency can be caused by lack of intake, by lack of intrinsic factor (for absorption which is made in the stomach) or by lack of the ileum where it is absorbed. - Deficiency first seen in macrocytic anemia, later as neurological disease.- Sources: most common in human diet is animal products, primary source is microbial. Animals then incorporate it into their tissue.Vitamin K:- Key thing to remember is that vitamin k is used in making protein factors needed for blood clotting- We make a large amount of this vitamin in our large intestine. It comes from microorganisms so it is very hard to develop a deficiency unless we take certain drugs.- Vitamin K in our diets needs fat absorption , like vitamin E, D and A WaterWater neededWater is not usually thought of as a nutrient, but as stated in the material, you need it to maintain life. You can live for a long time if you don’t eat vitamin B12, even folate, protein, but you will die very soon without water. You could think of this as the most essential nutrient.Need is based on a number of factors, but aside from heat, the best determination is the amount of calories someone has eaten. A general rule is 1 to 1.5ml per kcal. You also don’t want dark urine. The amount urine you want to produce is about 500 to 1000ml/d.Regulation of water balanceWater is not moved by itself from location to location within or out of the body. It followsthe movement of osmotically active compounds (sodium, chloride, potassium, protein) Water moves from a place of low osmotic pressure (low electrolytes) to a high osmotic pressure, so if you move sodium out of the body (i.e. swear, urine) water will follow. The main organ responsible for fluid control is the kidney. For most people thirst is a good feedback for need, but sometimes it comes too late. Therefore, young children should be careful to consume fluids before exercise and in the elderly the thirst response is poor and cannot be relied on.SodiumWe need very little sodium, however we can retain it very well (kidney is key). Some humans eat over 8 grams per day (which may increase their risk for hypertension), but most research suggests we need less than 0.5g/d (less than a teaspoon, much less than a typical American eats. We get very little sodium in the food we eat if it is NOT processed. Humans add a great deal of table salt, but the most is in the form of “hidden” sodium which is in added in processed foods. Corn flakes have more sodium than salted peanuts!Sodium is the major extracellular cation, while chloride (which follows sodium) is the major extracellular anion. Potassium is the main intracellular cation.Lifecycle - Adolescents have the highest energy requirements per day—While calories per kg are less than that of the infant, the adolescent has the highest need for calories per day compared to all other stages of lie. - Infants require the highest nutrient intake per kg—infants require 100-200 kcal/kg body weight(adults only require 30-40kcal/kg) This is the greatest calorie demand of any stage of life.- Adolescent boys have increased iron needs just like girls do. For girls the increased need is due to losses in menstrual cycle, for boys the need also increases due to increased muscle mass. - Most important period in development of lifelong dietary habits is years 1-4. - A contributing factor in anorexia nervosa may be in a family who is over-protective. In the classical family of the anorexic, the family is overly involved, overprotective and rigid.- Having a lower meat consumption is associated with a longer life expectancy. Lower meat consumption, along with eating less fat, and a diet higher in fruits and veggies and having moderate alcohol consumption are all associated with the longest life expectations.- Folate is important vitamin in the prevention of neural tube defects in the new born.AdolescentStress- this is a great time of stress; new body, new friends. Food can be a comfort or a