2Bone Mineralization and Growth Calcified structures include bones and teethCollagen and bone undergo constant remodelingOrganic matrix of bone is 90%–95% collagen fibersFormation of collagen requires protein,vitamin C, iron, copper, and zincOnce collagen is formed, mineralization beginsCalcium, phosphorus, magnesium, sodium, potassium, and carbonate ions form mineral matrixCalcium reserve: 0.4%–10% of total bone calcium in shapeless (amorphous) formFrom 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).
3From Nanci A: Ten Cate’s Oral Histology, ed 7. St. Louis: Mosby, 2008. Formation of TeethCrystalline structure of enamel is one of the most insoluble and resistant proteins knownComparable to hardness of quartzDentin contains the same constituents as bone, but its structure is more denseCementum is another bone-like substance, but because contains fewer minerals, is softer than boneFrom 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.
4Introduction to Minerals Minerals are inorganic elements that have many physiological functionsInorganic elements in body account for only about 4% of total body weight, or 6 lb for a 150-lb personMinerals subdivided into two categoriesThose required in larger amounts (major minerals)Those required in smaller amounts (micronutrients or trace elements)
5Physiological Roles: Calcium Most abundant mineral in thebody (~1200 g)99% in teeth and bonesFunctionsBone healthBlood clottingTransmit nerve impulsesMuscle contraction and relaxationMembrane permeabilityActivate certain enzymesSalivary calcium acts as bufferSaliva 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.
6Requirements: Calcium AI9–13 yo boys and girls1300 mg/day19–50 yo men and women1000 mg/day51–70+ yo men and women1200 mg/dayOnly 1 in 4 Americans meets AIfor calciumDuring 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.
7Requirements: Calcium Current levels of intakeMales ages 9 and olderAverage intake ~925 mg/day (71% of AI)Females ages 9 and olderAverage 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 buildpeak bone mass and prevent osteoporosis
8Calcium-to-Phosphorus Ratio Serum levels of calcium and phosphorus inversely relatedIf calcium level goes up, phosphorus level goes downIdeal calcium/phosphorus ratio for adults is 1:1Excessive intake of phosphorus compared with calcium reduces serum calcium concentrationCalcium requirements are increased when dietary phosphate is high as in the typical American diet
9Absorption: CalciumAbsorption regulated by hormones (parathyroid, estrogen, glucocorticoids, thyroid)Best absorbed when consumed in smaller amounts and ingested several timesduring the dayFactors decreasing absorption:Oxylates and phytates in grains,vegetablesReduced gastric acidityExcessive fiberLow-protein, low-phosphorus dietsDuring 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.
10Sources: 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 absorptionFortified soy and rice milkOther fortified foods (orange juice)SupplementsLimited bioavailabilityBetter absorbed when taken with foodCalcium citrate malate, calcium lactate, calcium citrate, and calcium sulfate have high absorption ratesCalcium 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):
11Hyperstates: Calcium Hypercalcemia-excess calcium levels in the blood Caused by:HyperparathryoidismOverdoses of cholecalciferolVitamin D poisoningExcessive calcium intake results in:Dizziness, flushing, nausea/vomiting, severe constipation, kidney stone formation, irregular heartbeat, tingling sensations, xerostomia, fatigue and high blood pressureMay inhibit iron and zinc absorptionRickets, osteoporosis, periodontal disease.
12Hypostates: Calcium Rickets Osteoporosis Abnormal ossification from vitamin D, calcium deficiencyOsteoporosis“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 childrenInadequate calcium intake in early life accounts for as much as 50% of difference in hip fracture rates in postmenopausal yearsFrom 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.
13Hypostates: CalciumReduction in total skeletal mass is directly related to reduction in mandibular bone density in women with osteoporosisPostmenopausal women who lost teeth also lost bone mineral of the whole body and femoral neck at greater rates than those who retained their teethSystemic bone loss appears to be a predictor of tooth loss in dentate postmenopausal womenInadequate calcium intake and periodontal diseaseStudy of NHANES data suggests a 56% risk of periodontal disease with calcium intakes 500 mg/day27% greater risk for those women consuming from 500 to 800 mg/day of calcium
14Physiological Roles: Phosphorus Phosphorus: second most abundant mineral in the body; about 85% in the skeleton and teethFunctionsFormation of bones and teethMuscle contraction and nerve activityComponent of phospholipids in cell membranes, DNA, and RNAEnergy metabolism (ADP)Buffer for the body
15Requirement and Source: Phosphorus RDAMen and women: 700 mg/daySourcesAbundant in foods—deficiency rareBest sources are milk products and meatsFood additive in baked goods, cheese, processed meats, and soft drinks
16Hyperstates: Phosphorus Hyperphosphatemia (serum level above 2.6 mg/dl) may occur in:HypoparathyroidismRenal insufficiencyExcessive amounts of phosphorus bind with calcium, resulting in tetany and convulsionsFrom Thibodeau GA, Patton KT: Anatomy & Physiology, ed 6. St. Louis: Mosby, 2007.
17Hypostates: Phosphorus Long-term ingestion of aluminum hydroxide antacidsStress conditions in calcium-to-phosphorus balanceMalabsorption conditions (sprue and celiac disease)During tooth development, phosphorus deficiency results in:Incomplete calcification of teethFailure of dentin formationIncreased susceptibility to caries
18Physiological Roles: Magnesium Bones contain almost two thirds of body’s magnesiumRole in bone and mineral physiologyCofactor for more than 300 enzymesNecessary for DNA and RNA synthesisRegulates transmission of nerve impulses and muscle contractionAssociated with vitamin D conversion in the liverFacilitates blood clottingFacilitates PTH secretionMagnesium 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.
19Requirements and Sources: Magnesium RDA (19-30 yr)Men: 400 mg/dayWomen: 310 mg/dayUL350 mg/day from nonfood sourcesSourcesDark green, leafy vegetablesWhole grains and nutsChocolate
20Hypostates: Magnesium Deficiency rare in healthy peopleCan occur w/prolonged vomiting, malabsorption, kidney disease, intestinal surgery, excessive use of OTC and medications (corticosteroids, diuretics)Present in nearly all chronic alcoholicsSymptoms of deficiency:Fragility of alveolar bone and gingival hypertrophyCardiac dysrhythmiasNeuromuscular hyperexcitability
21Hyperstates: Magnesium No evidence of overconsumption of magnesium from food sourcesKidney regulates magnesium and toxicity may cause kidney failureSymptoms:DiarrheaNauseaCramping
22Nutrition Directions: Magnesium Evidence suggests that magnesium may play an important role in regulating blood pressureThe 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 fatThe diet includes whole grains, fruits, vegetables and low-fat dairyFor more information about the DASH diet go to the National Heart, Lung, and Blood Institute website.
23Overview: FluorideIn a strict nutritional sense, fluoride is not a nutrient essential for health because it has no known metabolic functionHowever, because of benefits to dental and bone health, fluoride is considered a desirable element for humansFluoride ions can replace hydroxyl ions in the hydroxyapatite crystal lattice, making it more resistant to cariesFluoride 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.
24Physiological Roles: Fluoride Forms fluorapatite, which is more caries resistantSystemic fluoride results in changes to tooth morphology; increases tooth’s resistance to adherence of plaque biofilmFluoride in saliva also interferes with demineralizationHigher concentrations of fluorideinhibit Streptococcus mutans, Streptococcus sobrinus, and Lactobacillus speciesStimulates osteoblast proliferation and increases new mineral deposition in cancellous boneFrom 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):
25Requirements: Fluoride Absorption occurs in the stomachAI6–12 mo: 0.5 mg/day1–3 yr: 0.7 mg/day2–8 yr: 1.1 mg/day9–13 yr: 2.0 mg/day14–18 yr: 2.9–3.2 mg/day19+ yr: 3.1–3.8 mg/dayMost 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.
26Requirements: Fluoride UL6–12 mo: 0.9 mg/day1–3 yr: 1.3 mg/day4–8 yr: 2.2 mg/day9+ yr: 10 mg/daySourcesFluoridated waterBrewed teaOcean 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.
27Hyperstates: Fluoride Dental fluorosis (hypomineralization of enamel) directly related to fluoride exposure during tooth developmentVaries from white flecks, to white or brown staining, to brownish discoloration and varying degrees of enamel pittingIngestion of large amounts of fluoride in adults can result in adverse effects on skeletal tissue and kidney functionCourtesy Alton McWhorter, DDS, MS; Associate Professor Pediatric Dentistry; The Texas A&M University System; Baylor College of Dentistry; Dallas.
28Nutritional Directions Encourage use of fluoridated water for those >6 months of age and topical fluorides for adults and childrenEncourage low-fat dairy, whole grains, and vegetables as calcium and magnesium sourcesEvaluate use of supplements and refer to a medical provider and/or registered dietitian as neededStress need to minimize use of antacids and seek medical care for chronic heartburn