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Copyright © 2010, 2005, 1998 by Saunders, an imprint of Elsevier Inc.

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1 Copyright © 2010, 2005, 1998 by Saunders, an imprint of Elsevier Inc.
MINERALS ESSENTIAL FOR CALCIFIED STRUCTURES CHAPTER 8 Copyright © 2010, 2005, 1998 by Saunders, an imprint of Elsevier Inc.

2 Bone Mineralization and Growth
Calcified structures include bones and teeth Collagen and bone undergo constant remodeling Organic matrix of bone is 90%–95% collagen fibers Formation of collagen requires protein, vitamin C, iron, copper, and zinc Once collagen is formed, mineralization begins Calcium, phosphorus, magnesium, sodium, potassium, and carbonate ions form mineral matrix Calcium reserve: 0.4%–10% of total bone calcium in shapeless (amorphous) form From Bath-Balogh M, Fehrenbach MJ: Illustrated Dental Embryology, Histology, and Anatomy, ed 2. St. Louis: Saunders, 2006. Mineralization is the deposition of inorganic elements (minerals) on an organic matrix (mainly composed of protein in combination with some polysaccharides and lipids).

3 From Nanci A: Ten Cate’s Oral Histology, ed 7. St. Louis: Mosby, 2008.
Formation of Teeth Crystalline structure of enamel is one of the most insoluble and resistant proteins known Comparable to hardness of quartz Dentin contains the same constituents as bone, but its structure is more dense Cementum is another bone-like substance, but because contains fewer minerals, is softer than bone From Nanci A: Ten Cate’s Oral Histology, ed 7. St. Louis: Mosby, 2008. This special protein matrix in combination with a crystalline structure of inorganic salts makes enamel harder than dentin, comparable to the hardness of quartz. Enamel is more resistant to acids, enzymes, and other corrosive agents than dentin. Development of normal, healthy teeth is affected by metabolic factors, such as parathyroid hormone secretion, and the availability of calcium, phosphate, vitamin D, protein, and many other nutrients.

4 Introduction to Minerals
Minerals are inorganic elements that have many physiological functions Inorganic elements in body account for only about 4% of total body weight, or 6 lb for a 150-lb person Minerals subdivided into two categories Those required in larger amounts (major minerals) Those required in smaller amounts (micronutrients or trace elements)

5 Physiological Roles: Calcium
Most abundant mineral in the body (~1200 g) 99% in teeth and bones Functions Bone health Blood clotting Transmit nerve impulses Muscle contraction and relaxation Membrane permeability Activate certain enzymes Salivary calcium acts as buffer Saliva is supersaturated with calcium; thus saliva is a source of calcium to mineralize an immature or demineralized enamel surface and reduce susceptibility to caries. Both calcium and phosphate in saliva provide a buffering action to inhibit caries formation. From Fehrenbach MJ, Herring SW: Illustrated Anatomy of the Head and Neck, ed 3. St. Louis: Saunders, 2007.

6 Requirements: Calcium
AI 9–13 yo boys and girls 1300 mg/day 19–50 yo men and women 1000 mg/day 51–70+ yo men and women 1200 mg/day Only 1 in 4 Americans meets AI for calcium During growth periods, primarily from 9 to 18 years of age, the estimated requirement is higher because peak bone mass appears to be related to calcium intake during periods of bone mineralization (Table 8-1). About 8% to 90% of adult bone mass is acquired by age 18 in girls and 20 in boys. National Osteoporosis Foundation. Fast facts. Available at: Accessed on May 3, 2008. In 2004, the U.S. Surgeon General stated that “calcium has been singled out as a major public health concern today because it is critically important to bone health, and the average American consumes levels of calcium that are far below the amount recommended.” Only 1 in 4 Americans achieves the AI for calcium. US Department of Health and Human Services: Bone health and osteoporosis: A report of the Surgeon General. Rockville, MD: US Department of Health and Human Services, Office of the Surgeon General. Americans consumed only 1.8 cups of milk and milk products per person daily in Inadequate calcium intake can be attributed to (1) uninformed choices or not selecting adequate sources of calcium on a daily basis, (2) the mistaken belief that adults do not need milk or that milk contributes too many kilocalories to the diet, (3) economic hardships plus a lack of knowledge regarding inexpensive sources of calcium-rich foods, (4) lactose intolerance or allergies to dairy products, (5) access to and consumption of soda, or (6) dislike of calcium-rich foods. Wells HF, Buzby JC: Dietary assessment of major trends in U.S. food consumption, Economic Information Bulletin, No 33. Economic Research Service, Washington, DC, U.S. Department of Agriculture, March 2008.

7 Requirements: Calcium
Current levels of intake Males ages 9 and older Average intake ~925 mg/day (71% of AI) Females ages 9 and older Average intake ~657 mg/day (51% of AI) AI for those with self-diagnosed lactose intolerance ~320 mg/day (25% of AI) At high risk of inadequate intakes to build peak bone mass and prevent osteoporosis

8 Calcium-to-Phosphorus Ratio
Serum levels of calcium and phosphorus inversely related If calcium level goes up, phosphorus level goes down Ideal calcium/phosphorus ratio for adults is 1:1 Excessive intake of phosphorus compared with calcium reduces serum calcium concentration Calcium requirements are increased when dietary phosphate is high as in the typical American diet

9 Absorption: Calcium Absorption regulated by hormones (parathyroid, estrogen, glucocorticoids, thyroid) Best absorbed when consumed in smaller amounts and ingested several times during the day Factors decreasing absorption: Oxylates and phytates in grains, vegetables Reduced gastric acidity Excessive fiber Low-protein, low-phosphorus diets During periods of increased need, especially during growth and pregnancy and lactation, calcium absorption may increase to 60% of intake. Calcium absorption decreases with age, probably because of decreased gastric acidity. The rate of absorption is lowest in postmenopausal women because of diminished estrogen levels. From Thibodeau GA, Patton KT: Anatomy & Physiology, ed 6. St. Louis: Mosby, 2007.

10 Sources: Calcium Milk and dairy products Fortified soy and rice milk
Preferred sources of calcium because of high calcium, lactose, and other nutrient content that enhances calcium absorption Fortified soy and rice milk Other fortified foods (orange juice) Supplements Limited bioavailability Better absorbed when taken with food Calcium citrate malate, calcium lactate, calcium citrate, and calcium sulfate have high absorption rates Calcium from dietary sources positively influences estrogen metabolism, suggesting it has more favorable effects on bone health in postmenopausal women than calcium supplements. Box 8-2 lists portion sizes for various foods that provide approximately 300 mg of calcium. Napoli N et al: Effects of dietary calcium with calcium supplements on estrogen metabolism and bone mineral density. Am J Clin Nutr 2007 May; 85(5): Consumers in the United States annually spend more than $1 billion on the most popular dietary supplement, calcium. Calcium supplements result in small but significant reductions in bone loss. This strong trend toward the use of calcium supplements is especially evident in the older population. Heller L: Calcium and multivitamins drive U.S. market. Nutraingredients-USA 2008 May 5. Online: Accessed on May 9, 2008. Shea B et al: Meta-analysis of therapies for menopausal osteoporosis. VII. Meta-analysis of calcium supplementation for the prevention of postmenopausal osteoporosis. Endocr Rev 2002 Aug; 23(4):

11 Hyperstates: Calcium Hypercalcemia-excess calcium levels in the blood
Caused by: Hyperparathryoidism Overdoses of cholecalciferol Vitamin D poisoning Excessive calcium intake results in: Dizziness, flushing, nausea/vomiting, severe constipation, kidney stone formation, irregular heartbeat, tingling sensations, xerostomia, fatigue and high blood pressure May inhibit iron and zinc absorption Rickets, osteoporosis, periodontal disease.

12 Hypostates: Calcium Rickets Osteoporosis Abnormal ossification from
vitamin D, calcium deficiency Osteoporosis “Osteoporosis is a disease of adolescence” 90% of peak bone mass is attained by age yr and 99% by age yr  BMD associated with fractures in elder years, but also may predict fractures in children Inadequate calcium intake in early life accounts for as much as 50% of difference in hip fracture rates in postmenopausal years From Kumar V, Abbas AK, Fausto N: Robbins and Cotran Pathologic Basis of Disease, ed 7. Philadelphia: Saunders, 2005. Hypocalcemia, or deficient levels of calcium in the blood, results in tetany, a neuromuscular disorder of uncontrollable cramps and tremors involving the muscles of the face, hands, feet, and eventually the heart. Depressed serum calcium levels may be caused by hypoparathyroidism, some bone diseases, certain kidney diseases, and low serum protein levels.

13 Hypostates: Calcium Reduction in total skeletal mass is directly related to reduction in mandibular bone density in women with osteoporosis Postmenopausal women who lost teeth also lost bone mineral of the whole body and femoral neck at greater rates than those who retained their teeth Systemic bone loss appears to be a predictor of tooth loss in dentate postmenopausal women Inadequate calcium intake and periodontal disease Study of NHANES data suggests a 56%  risk of periodontal disease with calcium intakes  500 mg/day 27% greater risk for those women consuming from 500 to 800 mg/day of calcium

14 Physiological Roles: Phosphorus
Phosphorus: second most abundant mineral in the body; about 85% in the skeleton and teeth Functions Formation of bones and teeth Muscle contraction and nerve activity Component of phospholipids in cell membranes, DNA, and RNA Energy metabolism (ADP) Buffer for the body

15 Requirement and Source: Phosphorus
RDA Men and women: 700 mg/day Sources Abundant in foods—deficiency rare Best sources are milk products and meats Food additive in baked goods, cheese, processed meats, and soft drinks

16 Hyperstates: Phosphorus
Hyperphosphatemia (serum level above 2.6 mg/dl) may occur in: Hypoparathyroidism Renal insufficiency Excessive amounts of phosphorus bind with calcium, resulting in tetany and convulsions From Thibodeau GA, Patton KT: Anatomy & Physiology, ed 6. St. Louis: Mosby, 2007.

17 Hypostates: Phosphorus
Long-term ingestion of aluminum hydroxide antacids Stress conditions in calcium-to-phosphorus balance Malabsorption conditions (sprue and celiac disease) During tooth development, phosphorus deficiency results in: Incomplete calcification of teeth Failure of dentin formation Increased susceptibility to caries

18 Physiological Roles: Magnesium
Bones contain almost two thirds of body’s magnesium Role in bone and mineral physiology Cofactor for more than 300 enzymes Necessary for DNA and RNA synthesis Regulates transmission of nerve impulses and muscle contraction Associated with vitamin D conversion in the liver Facilitates blood clotting Facilitates PTH secretion Magnesium is involved in more than 300 enzymatic reactions, including energy metabolism, insulin activity, and glucose utilization. Some research has suggested that lower intakes of magnesium may lead to insulin resistance and/or type 2 diabetes mellitus.

19 Requirements and Sources: Magnesium
RDA (19-30 yr) Men: 400 mg/day Women: 310 mg/day UL 350 mg/day from nonfood sources Sources Dark green, leafy vegetables Whole grains and nuts Chocolate

20 Hypostates: Magnesium
Deficiency rare in healthy people Can occur w/prolonged vomiting, malabsorption, kidney disease, intestinal surgery, excessive use of OTC and medications (corticosteroids, diuretics) Present in nearly all chronic alcoholics Symptoms of deficiency: Fragility of alveolar bone and gingival hypertrophy Cardiac dysrhythmias Neuromuscular hyperexcitability

21 Hyperstates: Magnesium
No evidence of overconsumption of magnesium from food sources Kidney regulates magnesium and toxicity may cause kidney failure Symptoms: Diarrhea Nausea Cramping

22 Nutrition Directions: Magnesium
Evidence suggests that magnesium may play an important role in regulating blood pressure The DASH study (Dietary Approaches to Stop Hypertension) suggests HBP can be lowered by diet high in magnesium, potassium, and calcium, and low in sodium and fat The diet includes whole grains, fruits, vegetables and low-fat dairy For more information about the DASH diet go to the National Heart, Lung, and Blood Institute website.

23 Overview: Fluoride In a strict nutritional sense, fluoride is not a nutrient essential for health because it has no known metabolic function However, because of benefits to dental and bone health, fluoride is considered a desirable element for humans Fluoride ions can replace hydroxyl ions in the hydroxyapatite crystal lattice, making it more resistant to caries Fluoride may be passed from the mother via the placenta and incorporated into developing fetal tooth buds and bones. Fluoride during this stage is probably incorporated in the apatite crystals during formation. Due to lack of scientific studies determining optimal levels and benefits, prenatal fluoride supplementation is not recommended. SảRoriz Fonteles C et al: Fluoride concentrations in enamel and dentin of primary teeth after pre- and postnatal fluoride exposure. Caries Res 2005 Nov-Dec; 39(6): Primary teeth benefit from the presence of fluoride during tooth development beginning at 6 months of age. American Academy of Pediatric Dentistry Liaison with Other Groups Committee; American Academy of Pediatric Dentistry Council on Clinical Affairs. Guideline on fluoride therapy. Pediatr Dent ; 27(7 Suppl):90-91.

24 Physiological Roles: Fluoride
Forms fluorapatite, which is more caries resistant Systemic fluoride results in changes to tooth morphology; increases tooth’s resistance to adherence of plaque biofilm Fluoride in saliva also interferes with demineralization Higher concentrations of fluoride inhibit Streptococcus mutans, Streptococcus sobrinus, and Lactobacillus species Stimulates osteoblast proliferation and increases new mineral deposition in cancellous bone From Bird DL, Robinson DS: Torres and Ehrlich Modern Dental Assisting, ed 9. St. Louis: Saunders, 2009. The protective effect of fluoride against caries is greatest during the first 6 to 8 years of life, but adults as well as children continue to benefit from consumption of fluoridated water. Maupomé G et al: A comparison of dental treatment utilization and costs by HMO members living in fluoridated and non-fluoridated areas. J Public Health Dent 2007 Fall; 67(4):

25 Requirements: Fluoride
Absorption occurs in the stomach AI 6–12 mo: 0.5 mg/day 1–3 yr: 0.7 mg/day 2–8 yr: 1.1 mg/day 9–13 yr: 2.0 mg/day 14–18 yr: 2.9–3.2 mg/day 19+ yr: 3.1–3.8 mg/day Most fluoride is absorbed in the stomach, with small amounts also absorbed in the intestine. The rate and degree of absorption depend on the solubility of the source and the amount ingested at a particular time. Absorption of fluoride from sodium fluoride in water is estimated to be 80% to 90%. Incorporation of fluoride into bones and enamel is proportional to total intake and need.

26 Requirements: Fluoride
UL 6–12 mo: 0.9 mg/day 1–3 yr: 1.3 mg/day 4–8 yr: 2.2 mg/day 9+ yr: 10 mg/day Sources Fluoridated water Brewed tea Ocean fish w/bones (salmon, herring, sardines) The Centers for Disease Control and Prevention (CDC) credits water fluoridation with being one of the 10 most important public health measures of the 20th century. To ensure that everyone receives adequate amounts of fluoride, the IOM recommends that drinking water contain approximately 1 part per million (ppm) of fluoride (equivalent to 1 mg/L). In warmer climates where water consumption is higher, the optimal level of fluoride may need to be reduced. The range for optimal concentration of fluoride in community water supplies is 0.7 to 1.2 ppm. In 2006, approximately 69.2% of the U.S. population had access to optimally fluoridated drinking water; the revised goal, as stated by Healthy People 2010, targets 75% of the population. Water fluoridation reduces dental caries in children by 20% or more and helps prevent root surface caries and tooth loss in adults. Gillcrist JA, Brumley DE, Blackford JU: Community fluoridation status and caries experience in children. J Public Health Dent 2001 Summer; 61(3): For water bottled in the United States, the FDA requires fluoride be listed on the label only if the manufacturer adds fluoride during processing. Therefore, fluoride amounts in bottled water may or may not be denoted on the label. Food is not a major source of fluoride for adults. All foods contain some fluoride, but the amounts provided in vegetables, meats, cereals, and fruits are insignificant, containing between 0.2 and 1.5 ppm of fluoride (Table 8-8). Seafood may contain 5 to 15 ppm of fluoride. Brewed tea provides approximately 1 to 6 ppm of fluoride per cup, depending on the amount of tea, brewing time, and amount of fluoride in the water.

27 Hyperstates: Fluoride
Dental fluorosis (hypomineralization of enamel) directly related to fluoride exposure during tooth development Varies from white flecks, to white or brown staining, to brownish discoloration and varying degrees of enamel pitting Ingestion of large amounts of fluoride in adults can result in adverse effects on skeletal tissue and kidney function Courtesy Alton McWhorter, DDS, MS; Associate Professor Pediatric Dentistry; The Texas A&M University System; Baylor College of Dentistry; Dallas.

28 Nutritional Directions
Encourage use of fluoridated water for those >6 months of age and topical fluorides for adults and children Encourage low-fat dairy, whole grains, and vegetables as calcium and magnesium sources Evaluate use of supplements and refer to a medical provider and/or registered dietitian as needed Stress need to minimize use of antacids and seek medical care for chronic heartburn

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