Presentation Overview Functions, deficiency, toxicity & food sources of Ca, P, Mg as bone minerals. Osteoporosis types & risk factors. Functions, deficiency, toxicity & food sources of S as a protein based mineral.
Calcium Functions Bone & tooth structure. Blood clotting, muscle contraction, and nerve conduction.
Calcium (Ca) Deficiency & Toxicity Deficiency (<66% of DRI) Approx. < mg/day Adequacy DRI: 1,000-1,200 mg/day RDI: 1000 mg Toxicity (>UL) >2,500 mg/day Osteopenia Bone & tooth: stunted growth in children, low bone density, osteoporosis Normal Bone and tooth structure, muscle contraction, nerve conduction, blood clotting Hypercalcemia GI System: constipation, reduces absorption of iron, magnesium, zinc, and phosphorus. Other: kidney stones, calcium deposits in soft tissues Adult deficient, adequate, toxic values
Calcium: Food Sources Diary product sources: milk, yogurt, & cheese and foods made with diary products like pudding. Non dairy sources include fortified foods like soymilk and cereal, canned fish with the bones, spinach, turnip greens, tofu, broccoli, and kidney beans. The bioavailability of Ca is highest (~50%) from cruciferous vegetables, moderate (~30%) from dairy products & Ca fortified foods, low (~20%) from beans, nuts & seeds & lowest (<5%) from spinach.
Calcium in Dairy Foods ~ 30% bioavailability Calcium supplements should be taken if chronic low dietary intake occurs DRI: 1,000- 1,200 mg/day
Calcium in Non Dairy Foods 50% bioavailability Calcium supplements should be taken if chronic low dietary intake occurs Adult DRI: 1,000-1,200 mg/day
Calcium Supplements Calcium carbonate. Better absorbed when taken with food. –40% Calcium –500 mg tablet provides 300 mg Carbonate & fillers –200 mg Calcium Calcium citrate. Can be taken on an empty stomach. –21% Calcium –500 mg tablet provides 394 mg Citrate & fillers –105 mg Calcium Avoid: –Oyster shell, coral, bone meal, calcium phosphate, anti-acids supplements due to poor absorption, non-optimal design, and/or possible contamination.
Phosphorus Functions Bone & tooth structure. Important for the cells genetic material (DNA), phospholipids in cell membranes, energy transfer (ATP), phosphorylation reactions, & buffering systems (maintaining pH).
Phosphorus (P) Deficiency & Toxicity Deficiency (<66% of DRI) Approx. <460 mg/day Adequacy DRI: 700 mg/day RDI: 1,000 mg Toxicity (>UL) >4,000 mg/day Hypophosphatemia Bone & tooth: bone pain GI System: anorexia Neuro-Musccular: muscle weakness Other: general debility Normal bone & tooth structure, DNA, ATP, phospholipids, phosphorylation reactions, and buffering systems. Hyperphosphatemia GI System: reduced calcium absorption Other: calcification of non- skeletal tissues. The body strives for a calcium to phosphorus ratio in the blood stream of 1:1 Adult deficient, adequate, toxic values
Magnesium Functions Is needed to build bone, teeth, & proteins. Is a cofactor for more than 300 different enzymes. Functions in muscular contraction, blood clotting, and nerve impulse transmission.
Magnesium (Mg) Deficiency & Toxicity Deficiency (<66% of DRI) Approx. < mg/day Adequacy DRI: mg/day RDI: 400 mg Toxicity (>UL from supplements) >350 mg/day Rare in healthy people. Associated with hypocalcemia Central Nervous System: seizures Neuro-Musccular: muscle cramping, hyperexcitability Other: vitamin D metabolism interference Normal bone, tooth, and protein building; enzyme action, muscle contraction, blood clotting, and nerve impulse transmission From supplements and laxatives GI System: diarrhea, nausea, abdominal cramps, paralytic ileus Other: metabolic alkalosis, hypokalemia Adult deficient, adequate, toxic values
Magnesium: Food Sources Mostly plant foods: nuts, legumes, whole grains, dark green leafy vegetables, chocolate, and cocoa. ~80% lost in grain processing. Is not added back to processed foods.
Magnesium in Foods Adult DRI: mg/day
Osteoporosis the silent bone stalker TYPE 1 Postmenopausal TYPE 2 Senile Onset age50-70 years>70 years Bone lossTrabecularTrabecular & cortical GenderWomen:Men 6:1 Women:Men 2:1 Fracture siteWrist & SpineHip CauseEstrogen loss following menopause in women. Testosterone loss with age in men. Reduced calcium absorption, increased demineralization of bone, increased propensity to fall.
Bone Trabecular Bone: –The lacy inner structure of calcium crystals that supports the bone’s structure & provides a calcium storage bank. Cortical Bone: –The very dense bone tissue that forms the outer shell surrounding trabecular bone and comprises the shaft of a long bone.
Types of Fractures Wrists (least severe) –Most occur at age 50 or older –Is an early warning sign for osteoporosis. Spinal vertebrae (chronic back pain) –More likely at ages years –Fractures occur from bending or lifting –Several fractures leading to loss of height & spinal curvature Hips (most serious) –Most occur at 70 years or older –20% die with in 4 months –50% become institutionalized
Bone mass gained up to~ 25 yrs. Bone mass stabilized up to~ 40 yrs. –Exact age depends on physiological conditions. Bone mass is lost after ~50 yrs. –Exact age depends on physiological conditions. Peak Bone Mass
High Protein & Phosphorus intake Low calcium, vitamin D, magnesium, and fluoride intake Genetics (family history, small frame size) Lack of Exercise Very high fiber intake Smoking & Alcohol Menopause Osteoporosis Risk Factors
Sulfur Functions Needed for the biosynthesis of sulfur and sulfate containing compounds A component of organic compounds biotin, thiamin, cysteine, methionine, glutathione, taurine, and insulin. Helps stabilize protein shape and structure by forming disulfide bridges.
Sulfur (S) Deficiency & Toxicity Deficiency Not Established Adequacy DRI & RDI Not Established Toxicity UL is Not Established Sulfur has no known deficiency state. Protein deficiency would appear first. Normal biosynthesis of sulfur and sulfate containing compounds GI System: osmotic diarrhea and may contribute to inflammatory bowel disease such as ulcerative colitis
Sulfur: Food Sources Dried fruit, commercial breads, soy, sausages, tap water, some beverages, and protein-containing foods.
Summary Ca, P & Mg are important for bone & tooth structure while Mg & S are important in protein structure. These minerals have other critical functions in the body. Type 1 & 2 Osteoporosis. Deficiency &/or toxicities & food sources are identified for these minerals. References for this presentation are the same as those for this topic found in module 5 of the textbook