Transcript Calcium
IMPORTANCE OF CALCIUM Dr. Betty J. Larson, LRD, FADA Concordia College Moorhead, MN 56562 Osteoporosis Prevention Blood Pressure Control (Calmodulin) Impact of Calcium Muscle Contraction Bone Calcification Blood Clotting (thromboplastin) Nerve Impulse transmission Tooth Formation Calcium and Hypertension When animals are deprived of calcium blood pressure increases. Increasing calcium in animals lowers blood pressure or lessens the development of high blood pressure. Hypertension is more prevalent in populations with a low calcium intake. Calcium and Hypertension Osteoporotic women have a 2-3 fold increase in hypertension. Increasing calcium decreases blood pressure. McCarron (1999) demonstrated that men with higher blood pressure levels also had lower bone mineral density and bone mineral content. DASH diet demonstrated that a low fat diet rich in dairy, fruits and vegetables could significantly reduce blood pressure. Journal of the American College of Nutrition (1999). 18(5):373S-412S. Calcium in the Prevention of Kidney Stones Dairy Foods Prevent Colon Cancer Vitamin D and Calcium Prevent Breast Cancer Calcium Control of Blood Pressure Implications for Osteoporosis Implications for weight management PMS Daily consumption of 1,200 mg of calcium may decrease some adverse side effects of PMS including psychological symptoms, food craving, and water retention Dairy’s Role in Weight Management Calcium may play an important role in the regulation of energy metabolism and may result in a reduction of body fat and an acceleration of weight and fat loss during caloric restriction. Dairy sources of calcium may have a substantially greater effect than supplemental or fortified sources. Increasing dietary calcium or dairy intake may reduce future weight gain. Nutrients found in dairy, including calcium, may contribute to the reduction of body weight, body fat and insulin resistance syndrome. Increasing calcium intakes to recommended levels may reduce the incidence of overweight and obesity by 60-80% in a population. Low daily calcium intake was associated with greater body fat and body weight, particularly in women. Benefit of Dairy Foods Dairy foods provide calcium, vitamin A, thiamin, riboflavin, B12 , magnesium, and phosphorus. Milk provides vit D CLA Calcium Sources Calcium content is highest in dairy products One 8-ounce glass of skim milk contains about 300 mg which supplies about 1/3 of the RD for an adult Equivalent dairy foods are 1.5 oz of cheese, 1 c yogurt, 1.75 c of ice cream Other good sources include fish with small bones such as sardines, canned salmon, dark green leafy vegetables (broccoli, kale, turnip greens), tofu, legumes, nuts, fortified OJ or fortified cereals DV for calcium is 1,000 mg Dietary Calcium Intake of Females in mg – 75% of F do not consume the AI for calcium 1400 1200 1000 800 Intake Ideal 600 400 200 0 age age age 15- 18- 25- 35- 45- 551-2 3-5 12- 17 24 34 44 54 64 14 Factors that Enhance Calcium Absorption Acid Normal GI Motility Calcium-Phosphorus Ratio Vitamin D Need for Calcium Lactose PTH Factors that Hinder Calcium Absorption Inadequate Vitamin D Intake Alkaline Conditions Impaired GI Motility Imbalance in Calcium:Phosphorus Ratio Excess Intake of Iron, Zinc, or Magnesium Phytic or Oxalic Acid Calcium and Sodium Excess sodium can increase calcium excretion For every 500 mg increase in urinary sodium excretion there is about a 10 mg increase in urinary calcium loss. Calcium, Protein, and Exercise Excessive protein intake may lead to calcium excretion. About 1 mg of calcium is lost for every gram of protein consumed. Intense exercise may increase urinary loss of calcium Coffee, alcohol and calcium High intakes of coffee and alcohol may increase calcium loss from the body Up to five cups of coffee and moderate alcohol consumption appear to have little effect on calcium balance If Blood Calcium is Too Low It will be a signal to Parathyroid Gland to secrete Parathormone Viamin D raises calcium absorption in the gut PTH & Vitamin D promote kidney reabsoprtion of calcium PTH & D stimulate calcium release from bone Bioavailability Calcium absorption from broccoli, cabbage and kale is good, but the calcium content per serving is much less than that for milk Osteoporosis Porous Bones Back Pain Spontaneous Fracture Loss of Height Dowager’s Hump Dowager’s Hump Osteoporosis Prevention Adequate Calcium Intake Increased Exercise Adequate Vitamin D Intake Avoid Excessive Protein Intake, Alcohol, Fiber and Cigarettes Resources for health professionals on calcium www.nationaldairycouncil.org Calcium Content of Food Broccoli: 36 mg per 1/2 cup Sardines: 324 mg per 3 oz Milk: 316 mg per cup Pork & Beans: 77 mg per 1/2 cup Cheddar Cheese: 305 mg per 1 1/2 oz Almonds: 80 mg per 2 Tbs Calcium Supplements Consumers Union notes that most people absorb calcium from different preparations equally well and recommends pills that deliver calcium at the lowest price. Over age 50 may do better with chewable calcium-carbonate Check label for calcium content per tablet – range from 50-600 mg. Best choice a tablet with about 200 mg with snacks or small meals – gastric acidity and slower transit time in the gut may enhance absorption Calcium Toxicity NEVER FROM FOODS Excess Vitamin D with Calcium Supplements Symptoms include abnormal heart contractions, constipation, development of kidney stones May interfere with absorption of key minerals notably iron and zinc Supplements without food may contribute to oxalate stones in the kidney Osteoporosis in Sports Concern about disturbed calcium metabolism in young ahtletes in endurance or weight control sports. Female Athlete Triad – disordered eating, amenorrhea, osteoporosis Restrictive diets and excessive exercise may affect hormone status including the hypothalamus and pituitary glands resulting in reduced levels of estrogen. Athletic Amenorrhea Amenorrheic athletes were found to have significantly less bone mineral content in the spine and other bones, including the femur. Increased dietary calcium may be useful in maintaining bone but limited research. Four glasses of skim milk provide 1200 mg of calcium. Other nutrients such as protein, magnesium, zinc, copper, iron, fluoride and vitamins A, C, D, and K are also required for bone metabolism. How can you get your peers to consume adequate calcium? 2001 jingle to “Here comes Santa Claus” Here comes calcium, here comes calcium right down mineral lane. Bones growing stronger, blood clotting faster don’t deny your calcium need. Calcium everyone, not just anyone, oh what a wonderful thing. Broccoli, Sardines, Milk and Pork & Beans, drink your calcium today. Phosphorus Phosphorus is part of ATP for energy processes Bones and Teeth Acid-Base balance Lipids contain phosphorus as part of their structure in phospholipids Phospholipids are major components of cell membranes Important for muscle contraction in ATP and PCr Glucose also needs to be phosphorylated in order to enter glycolysis to produce energy Phosphorous is found in Animal Meat, Protein seafood Eggs Milk Cheese Processed foods such as soda pop Nuts, dried beans and peas, grain products Phytate Phosphorus is part of phytate that might diminish absorption of minerals like calcium, iron, zinc and copper by forming insoluble phosphate salts in the intestine. Recommended calcium phosphorus ratio is 2:1 calcium to phosphorus or 1:1. Too much phosphorus might impair calcium abosrption Intake Deficiency of phosphorus is very rare – recovering alcoholics or with excess antacids PhosFuel –phosphorus to enhance exercise performance but in the past 50 years most research has discredited use of phosphorus supplementation on athletic performance and they may create imbalance with calcium. It may have a limited impact on perceived exertion. Magnesium Involved in over 300 enzyme systems A major role is to act as a catalyst in the reaction that adds the last phosphate to ATP Acts together with calcium in muscle contraction and blood clotting; while calcium promotes the process, magnesium inhibits the process. Helps prevent dental decay by holding calcium, in the tooth. Helps prevent bone fragility PART OF AN ENZYME NECESSARY FOR GLUCOSE METABOLISM IN THE MUSCLE AND FOR GLUCONEOGENESIS. Magnesium Requirement Almost 3 of every 4 Americans do not meet need Found in chocolate, nuts, seafood, green leafy vegetables, black beans, and whole grain products. ½ cup of shrimp or cooked spinach contains about 20% of the RDA A glass of skim milk has 10% of the RDA Hard water may contain up to 20 mg of magnesium/liter Some bottled waters may have over 100 mg/liter UL is 350 mg FROM SUPPMENTS – not an issue with food as absorption varies from food 25-60% Magnesium Deficiency Can develop with prolonged diarrhea, use of diuretics or excess alcohol Symptoms include apathy, muscle weakness, muscle twitching and tremor, muscle cramps (particularly in the feet) and cardiac arrhythmias Lack of Mg may contribute to increased blood pressure No data available on the benefit of magnesium supplements for athletic performance. Excess Mg may cause nausea, vomiting, diarrhea