BONE VITAMIN D CALCIUM MAGNESIUM AND PHOSPHORUS Cortical is dense compact hard shell Trabecular is more metabolically active and more likely to be biologically broken with Osteoporosis or Osteopenia Trabecular usually is affected by the hip girdle arm spine and long bones It has a high turnover rate and is available for resorption Its density can be measured by DEXA Ca2 when we drink it is actually for the restoration of the amount in the blood Our blood once refilled will send the rest to bones for storage Hydroxyapatite crystal lattice found in bones and teeth made of Ca2 salts They are laid on top of matrix Down regulated by PTH calcitriol Becomes embedded in matrix and becomes osteocytes Maintains integrity of surrounding bone Proteins in bone Collagen Osteonectin binds to both Ca2 and collagen Osteopontin binds hydroxyapatite and bone cells Up regulated by PTH Calcitriol Down regulated by Calcitonin Help maintain bone calcium o Bad for bone but good for your body Bone is living tissue Osteoclasts still work with Ca2 intake Fibroblasts form collagen 1 2 Long rod shaped protein that gives strength Requires iron vitamin C and vitamin D Reticulocytes a Make RBC b Make leukocytes Dexa Vitamin D Phosphorus Weight loss Key Players Calcium Vitamin D Magnesium Phosphorus 70 yrs 20 You must only know these from the chart given in notes The rest of the notes will be typed Sources of vitamins and minerals for bone Dairy products are some of the highest sources such as milk cheese and yogurt Vegetable sources include turnip or mustard greens broccoli cauliflower legumes tofu but not spinach rhubarb or Swiss chard Those three are not the best sources because they have compounds called oxalates These bind to Ca2 and keep it from getting absorbed This can cause stones in the kidneys Seafood such as salmon sardines with bones clams oysters and anchovies are also good sources Lastly fortified foods such as orange juice Vegetable spreads are also good The average adults absorb 30 of Ca2 consumed and growing children absorb up to 75 35 25 Supplements Calcium citrate malate Calcium monophosphate Calcium carbonate Calcium carbonate can be gotten from all natural sources which can be a good thing but these all natural sources may have other minerals in it such as lead and aluminum because they come from oysters or dolomite so make sure you get it from a reputable source Bone meal preparations may also contain lead Supplements vitamins and minerals do not go through the same pathway as food does but there is a natural supplement foundation that checks for this problem NSF is one group 40 Phosphorus You can get it form organic products such as animals This includes Meat poultry fish milk and eggs Think about all the phosphorus that we use for energy reactions ATP So inorganic phosphates come from plant sources such as legumes cereal and whole grains These are often in the form of phytic acid or phytates Other sources include coffee tea and soft drinks Magnesium Coffee tea cocoa darker is better than milk chocolate whole grains legumes green leafy vegetables chlorophyll and hard water tap water You know you have hard water if you get the white mineral scale buildup around your faucets It is used to stabilize ATP so every ATP has one Mg to hold the phosphates together Filtering water can decrease your mineral consumption Vitamin D Animal sources such as beef eggs fortified milk and dairy not much quality control and saltwater fish such as salmon and tuna Fortified sources include breads and cereals We also get Vitamin D from plants almost none and sunlight 10min 10ug Depends on people because darker skin older more up north and fatter people tend to have less vitamin D from cholesterol Vitamin D forms include Ergocalciferol D2 and Cholecalciferol D3 D2 comes from plants must be put through lab and are sold commercially D3 are from animal products and come from cholesterol Ergocalciferol or pre vitamin D2 Ergocalciferol or 1 25 OH 2D2 Cholecalciferol or 25 OH D3 You can use both of these forms in your body The picture depicts the order conversion and remember that Calcitriol is the active form of Vitamin D and is what affects absorption of Ca2 In the liver we convert Cholecalciferol to Calcidiol In the kidney we convert Calcidiol to the active hormone Calcitriol by the enzyme 1 hydroxylase Activity of enzyme is increased by low plasma Ca2 and PTH parathyroid hormone Its activity is decreased by high cholesterol concentrations and dietary phosphorus Functions of Vitamin D Regulates calcium and phosphorus Calcium in the non osseous 1 regulates enzyme activation free calcium induces Phospholipase A which liberates FA from glycerol backbone blood clotting muscle contraction requires Mg nerve impulses and hormones Lack of calcium can cause intermittent muscle contractions which are painful For osseous 99 we have Ca2 functioning in bone formation The functions of phosphorus include skeletal mineralization energy in the form of ATP and phosphorylase reactions We can get vitamin D form sun and food So if we eat it we are in the lumen of the intestine Let us say we eat fortified milk That milk has vitamin D Calcium and fat Because it has fat we are going to surround it by bile salts and emulsify fat and fat soluble vitamins Fat soluble vitamins passively diffuse FA and Vitamin D from the milk passively diffuse into enterocyte Vitamin D and fat leaves the enterocyte by chylomicron The chylomicron remnants then deposit FA in other tissues and the V D goes to the liver to be transformed to D 3 after entering the liver by receptor medicated endocytosis We can also get Vitamin D from the sunlight hitting our skin The UVB then turns to cholesterol and then Cholecalciferol D3 D3 then exits and enters the liver with the addition of DBP Once in the liver D3 is converted to Calcidiol by 25 hydroxylase To get the Calcidiol to the kidney DBP is used again Calcidiol is then converted to Calcitriol by 1 hydroxylase in the kidney This then exits the kidney and enters tissues via VDR How does Vitamin D Calcitriol maintain calcium With PTH we target three main tissues intestine bone and kidney Our intestine is how it gets into our body Our bone is our savings bank of Calcium and kidney is how it is going to leave our body We can absorb more pull out of our savings or excrete less if we need Calcium Calcitriol and PTH work to increase Ca2 by doing these three things If our blood calcium levels drop it will tell intestine to
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