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Background
Calcium is required for the conventional growth and upkeep of the skeleton in addition to for the correct functioning of neuromuscular and cardiac operate. It’s saved within the enamel and bones the place it offers construction and energy. Low intakes of calcium have been related to a situation of low bone density referred to as osteoporosis which is kind of frequent in western cultures and which frequently leads to bone fracture. It is among the main causes of morbidity amongst older Australians and New Zealanders, significantly postmenopausal girls. Calcium consumption all through life is a significant factor affecting the incidence of osteoporosis, nevertheless different components, notably satisfactory vitamin D standing and train, additionally play a job.
Bone mass will increase by about sevenfold from start to puberty and an additional threefold throughout adolescence (Peacock 1991) after which stays secure till about age 50 in males and till the menopause in girls. In the course of the adolescent development spurt, the required calcium retention is 2 to 3 occasions increased than that required for the event of peak bone mass which happens concurrently most peak (Nordin et al 1979).
For about 5-10 years each throughout and after the climacteric and menopause (Heaney 1986), girls lose bone extra quickly than males (2%-3% per yr). Thereafter, the age-related loss in each sexes is about 0.5 to 1.0% every year. All the physique’s calcium reserve is saved within the skeleton. The dimensions of the reserve is straight affected by the physique’s exterior calcium steadiness which will depend on the relation between calcium consumption and absorption on the one hand and losses of calcium by the pores and skin, kidney and bowel on the opposite.
Till not too long ago, the quantity of dietary calcium wanted to exchange losses by sweat had not been included in estimates of calcium necessities. This omission accounts to a big extent for an obvious improve in calcium consumption suggestions seen within the current revisions of the FAO:WHO (2001) and US:Canadian (FNB:IOM 1997) suggestions and within the present revision of the Australian/New Zealand suggestions.
Calcium steadiness deteriorates at menopause when there’s a decline in intestinal calcium absorption and/or a rise in urinary calcium excretion. In publish menopausal girls, there’s proof {that a} excessive calcium consumption will sluggish the speed of bone loss and will scale back the danger of fracture (Cumming & Nevitt 1997, Dawson-Hughes et al 1990, Elders et al 1994, Nordin 1997, Prince et al 1995, Reid et al 1993, 1995) nevertheless it has been advised that the advance could attenuate over time (Mackerras & Lumley 1997).
A scientific evaluate was additionally undertaken by Cumming & Nevitt (1997) of 14 research of calcium dietary supplements (together with 4 RCTs), 18 research of dietary calcium and hip fracture (no RCTs), and 5 research of dietary calcium and different fracture websites (no RCTs). The 4 RCTs of calcium dietary supplements (imply calcium dose 1,050 mg) discovered relative danger (RR) reductions of between 25% and 70%. Cochrane evaluations by Shea et al (2003, 2004) additionally concluded that calcium supplementation had a small optimistic impact on bone density and a development in the direction of discount in vertebral fractures however concluded that it was unclear if calcium reduces the incidence of non-vertebral fractures. Nonetheless, one current massive intervention trial in 5,292 beforehand ambulatory aged individuals who had already skilled a fracture confirmed no impact on the incidence of additional fractures of calcium and/or vitamin D dietary supplements at ranges of 1,000 mg calcium or 20 µg day by day oral vitamin D3 alone or together (Grant et al 2005).
Calcium is discovered predominantly in milk and milk-based meals, with smaller quantities in bony fish, legumes and sure nuts, fortified soy drinks and breakfast cereals. Consumption of vegetarian diets could affect calcium wants due to their comparatively excessive oxalate and phytate content material, nevertheless, on steadiness, lacto-ovo-vegetarians seem to have comparable calcium intakes to omnivores (Marsh et al 1980, Pedersen et al 1991, Reed et al 1994) and comparable urinary excretion (Lloyd et al 1991, Tesar et al 1992).
Vegans have a decrease calcium consumption than vegetarians and omnivores (Larsson & Johansson 2002, New 2004), nevertheless one research by Kohlenberg-Mueller & Raschka (2003) has proven that each lactovegetarians and vegans can attain calcium steadiness. Intakes of calcium in adults in Australia and New Zealand common about 850 mg of which about 40% comes from non-milk sources.
For pure meals sources of calcium, content material is of equal or higher significance than bioavailability. The effectivity of calcium absorption varies throughout meals as calcium could also be poorly absorbed from meals wealthy in oxalic acid (eg spinach, rhubarb, beans) or phytic acid (seeds, nuts, grains, sure uncooked beans and soy isolates). Absorption from soy milk could be, however just isn’t all the time, as excessive as that from milk. In comparison with milk, calcium absorption from dried beans is about 50% and from spinach, 10%.
Bioavailability from non-food sources (eg dietary supplements) will depend on the dosage and whether or not they’re taken with a meal. In standardised research of 250 mg calcium dietary supplements given with a breakfast meal, absorption from dietary supplements gave fractional absorption charges of 25-35% in comparison with a charge for calcium from milk of 29% (Heaney et al 1989, 1990, Miller et al 1988, Smith et al 1987). Effectivity of absorption of calcium from dietary supplements is biggest at doses of 500 mg or much less (Heaney et al 1975, 1988), however as soon as the lively transport mechanism is saturated, solely 5-10% of further calcium is absorbed.
Sodium consumption may also have an effect on calcium necessities as sodium and calcium excretion are linked within the kidney tubules (Nordin & Polley 1987, Matkovic et al 1995, O’Brien et al 1996, Devine et al 1995) – 2,300 mg of sodium takes out about 40 mg of calcium. The quantity of protein within the weight loss program may also have an effect on calcium want. Excessive intakes of protein improve urinary calcium excretion (Linkswiler et al 1981, Margen et al 1974) – every gram of protein takes out 1 mg of calcium. In distinction, diets which are significantly low in protein have additionally been proven to be of concern by way of bone well being, presumably attributable to lowered calcium absorption (Cooper et al 1996, Geinoz et al 1993, Hannan et al 2000, Kerstetter et al 2003a,b). The impact of protein on calcium retention is unclear (Delmas 1992, Walker & Linkswiler 1972).
Indicators which were used to evaluate calcium necessities embrace steadiness research, factorial estimates of necessities or evaluation of modifications in bone mineral density and bone mineral content material. In setting the Australian and New Zealand suggestions, a steadiness strategy used for the sooner Australian /New Zealand RDIs and utilized by FAO:WHO of their 2001 revision of Human Vitamin and Mineral Necessities (FAO:WHO 2001) was adopted. Different approaches, equivalent to the varied strategies utilized by the US:Canadian DRI evaluate (FNB:IOM 1997) give extensively various and inconsistent outcomes, making interpretation problematic.
For adults, the outcomes of 210 steadiness research on regular people quoted within the FAO:WHO report have been used to calculate calcium necessities. The estimate was primarily based on the consumption at which excreted calcium equals web absorbed calcium, including an allowance for insensible losses. In postmenopausal girls, allowance was made for a further lack of calcium in urine.
The calcium necessities for different age/gender/physiological teams, for whom there have been few steadiness research, have been estimated from the quantity of calcium that every group should soak up in an effort to meet compulsory calcium losses, along with a consideration of their fascinating calcium retention after which calculation of the consumption required to offer this needed charge of calcium absorption. The one exception to this was for infants in whom the focus of calcium in breast milk fashioned the idea of suggestions.
1 mmol calcium = 40 mg calcium
Suggestions by life stage and gender
Infants
Rationale: The AI for 0-6 months was set by multiplying collectively the common consumption of breast milk (0.78 L/day) and the common focus of calcium in breast milk (264 mg/L) from 10 research reviewed by Atkinson et al (1995), and rounding. System-fed infants require further intakes within the neighborhood of 350 mg/day as calcium is much less bioavailable in system. The AI for infants 7-12 months was set by including an estimate for calcium from breast milk at this age, to an estimate of consumption from supplementary meals. A breast milk quantity of 0.60 L/day was assumed at older ages (Dewey et al 1984). The focus of calcium in breast milk at this age averages 210 mg/L (Atkinson et al 1995). This provides a contribution of 126 mg/day from breast milk that’s added to 140 mg/day from complementary meals (Abrams et al 1997, Specker et al 1997) and rounded, giving an AI of 270 mg/day.
Youngsters & adolescents
Rationale: The EAR for kids 1-8 years was set by modelling the parts of calcium necessities, together with a element for skeletal development (FAO:WHO 2001). Necessities have been estimated from knowledge on accumulation of whole-body calcium, which was transformed to a day by day charge of calcium accretion. This, along with consideration of urinary calcium losses, dermal losses and day by day skeletal increments, offers an estimate of day by day web absorbed calcium wants. For kids 1-8 years, this leads to a determine of about 220 mg. EARs have been set for this age band primarily based on the estimated quantities wanted – 440 mg/day on common – to offer this degree of absorbed calcium, assuming absorption charges of 1 SD above these of adults. A decrease determine of 360 mg/day was utilized to the youthful age band as their necessities will likely be much less and 520 mg/day to the older group, on an approximate physique weight foundation. The RDI was set assuming a CV of 15% for the EAR (as variation within the wants of kids and adolescents are more likely to be higher than for adults) and rounding, giving an RDI of 500 mg/day for 1-3 year-olds and 700 mg/day for 4-8 year-olds.
From Sep 11 years of age, calcium accretion charges are just like these in youthful kids with EARs being 800 mg/day, assuming absorption at 1 SD above that for adults. There’s a putting improve within the charge of skeletal calcium accretion from 12 to 18 years of age (FAO:WHO 2001). For this age group, web absorbed calcium must be 440 mg. Assuming excessive calcium absorption (+2 SDs above that for adults) this requires an EAR of 1,046 mg/day. Assuming a CV of 15% for the EAR, this provides an RDI of 1,300 mg within the older adolescents. For kids aged Sep 11 years who’ve bodily matured a lot sooner than common, the suggestions for 12-18 year-olds could also be extra acceptable.
Adults
Rationale: The EAR for adults was set by calculating calcium requirement because the consumption at which excreted calcium equals web absorbed calcium, primarily based on the outcomes of 210 steadiness research on 81 topics (FAO:WHO 2001). This happens at an consumption of 520 mg/day to which losses by sweat should be added. Insensible losses of calcium have been estimated at 60 mg/day (Charles et al 1983, Hasling et al 1990). Taking the low absorption that happens at about 500 mg/day into consideration, a further consumption of 320 mg is required to cowl these losses, growing the EAR to 840mg. At menopause, a further 30 mg is misplaced in urine (Nordin et al 1999) and absorption most likely decreases (Heaney et al 1989, Nordin 1997) elevating the EAR to 1,100 mg. This provides an RDI of 1,000 mg/day for males and premenopausal girls, and 1,300 mg for postmenopausal girls (EAR+2SD = RDI), assuming a CV of 10% for the EAR.
Little recognized about calcium metabolism within the aged, however absorption is understood to lower with age in each sexes (Ebeling et al 1994, Morris et al 1991, Want et al 1998). Information for elevated want at menopause are sturdy however these for older males usually are not. As a precaution, a further common requirement of 250 mg/day is really useful, translating to a further 300 mg for the RDI.
Being pregnant
Rationale: The EAR and RDI for being pregnant have been primarily based on the wants of the mom plus any further allowance for the foetus and merchandise of conception. The foetus retains about 25-30 g, largely within the third trimester of being pregnant, however there’s proof that being pregnant is related to elevated calcium absorption (Cross et al 1995a, Heaney & Skillman 1971, Kent et al 1991, Kumar et al 1979). Vital will increase in maternal calcium accretion, bone turnover and intestinal absorption early in being pregnant earlier than foetal bone mineralisation have additionally been proven (Heaney & Skillman 1971, Purdie et al 1988).
Dietary calcium consumption doesn’t seem to affect modifications in maternal bone mass in being pregnant (Raman et al 1978) and there’s no relationship between the variety of earlier pregnancies and bone mineral density (Alderman et al 1986, Koetting & Warlaw 1988, Kreiger et al 19832, Walker & Linkswiler 1972, Wasnich et al 1983) or fracture danger (Johansson et al 1993). Certainly, some research present a optimistic correlation between variety of kids born and radial bone mineral density or whole physique calcium (Aloia et al 1983) in addition to discount within the danger of hip fracture (Hoffman et al 1993).
These findings assist the idea that maternal skeleton just isn’t used for foetal calcium wants. The work of Prentice (2003) additionally confirms no further want for calcium in being pregnant. The out there info thus doesn’t assist the necessity for extra dietary consumption in being pregnant as maternal adaptive mechanisms together with enhanced effectivity of absorption greater than meet the extra wants within the final trimester. The implication is that ordinary calcium consumption is ample to satisfy the calcium requirement within the pregnant state.
Lactation
Rationale: Throughout being pregnant, 210 mg calcium/day on common is secreted in milk. The first supply of this calcium seems to be from elevated maternal bone resorption (Affinato et al 1996, Dobnig et al 1995, Kent et al 1990) which is unbiased of calcium consumption (Cross et al 1995b, Sowers et al 1995, Specker et al 1994). This bone loss is changed after weaning. There isn’t any proof that the calcium consumption of lactating girls needs to be elevated above that of non-lactating girls.
Higher Stage of Consumption – “calcium ul”
Rationale: Due to the inverse relationship between fractional calcium absorption and calcium consumption, a further consumption of 1,000 mg added to a typical western weight loss program would solely improve calcium in urine by about 60 mg. Urinary calcium rises slowly with consumption and danger of growing kidney stones (nephrolithiasis) from calcium dietary supplements is due to this fact negligible. Poisonous results of calcium have solely been seen when calcium is given in excessive doses because the carbonate as an antacid. The result’s hypercalcaemia with renal calcification and renal failure and is called the milk alkali syndrome or MAS (Burnett et al 1949).
Utilizing MAS because the critically outlined endpoint, a LOAEL of about 5 g could be recognized for adults from 16 research involving 26 topics (FNB:IOM 1997).
A UF of two takes into consideration the potential for elevated danger of excessive calcium consumption, given the comparatively frequent incidence of kidney stones in Australia and New Zealand, the truth that hypercalciuria in folks with renal stones has been proven to happen at intakes as little as 1,700 mg /day in males and 870 mg in girls (Burtis et al 1974) and concern that calcium will intrude with absorption of different minerals equivalent to zinc and iron in weak populations. The UL is due to this fact set conservatively at 2,500 mg/day.
As there’s little proof for different age and physiological teams, this determine is used for all age and gender teams and physiological states, significantly in relation to the necessity to stop interference with zinc and iron absorption.
References
Abrams SA, Wen J, Stuff JE. Absorption of calcium, zinc and iron from breast milk by 5- to 7-month-old infants. Pediatr Res 1997;41:1-7.
Affinito ZP, Tommaselli GA, DiCarlo C, Guida F, Nappi C. Adjustments in bone mineral density and calcium metabolism in breast-feeding girls: A one yr follow-up research. J Clin Endocrinol Metab 1996;81:2314-8.
Alderman BW, Weiss NS, Daling JR, Ure CL, Ballard JH. Reproductive historical past and postmenopausal danger of hip and forearm fracture. Am J Epidemiol 1986;124:262-7.
Aloia JF, Vaswani AN, Yeh JK, Ross P, Ellis Ok, Cohen S. Determinants of bone mass in postmenopausal girls. Arch Intern Med 1983;143:1700-4.
Atkinson SA, Alston-Mills BZP, Lonnerdal B, Neville MC, Thomson MP Main minerals and ionic constituents of human and bovine milk. In: Jensen RJ, ed. Handbook of milk composition. California: Educational Press, 1995. Pp 93-619.
Burnett CH, Commons RM, Albright F, Howard JE. Hypercalcaemia with out hypercalciuria or hypophosphatemia, calcinosis and renal insufficiency. A syndrome following extended consumption of milk and alkali. N Engl J Med 1949;240:787-94.
Burtis WJ, Homosexual L, Insogna KL, Ellison A, Broadus AE. Dietary hypercalciuria in sufferers with calcium oxalate kidney stones. Am J Clin Nutr 1974;60:424-9.
Charles ZP. Jensen FT, Mosekilde L, Hansen HH. Calcium metabolism evaluated by 47Ca Kinetics: Estimation of dermal calcium losses. Clin Sci 1983;65:415-22.
Cooper C, Atkinson EJ, Hensrud DD, Wahner HW, O’Fallon WM, Riggs BL, Melton LJ third. Dietary protein consumption and bone mass in girls. Calcif Tissue Int 1996;58:320-5.
Cross NA, Hillman LS, Allen SH, Krause GF, Vieira NE. Calcium homeostasis and bone metabolism throughout being pregnant, lactation and postweaning: a longitudinal research. Am J Clin Nut.1995a;61:514-23.
Cross NA, Hillman LS, Allen SH, Krause GF. Adjustments in bone mineral density and markers of bone remodelling throughout lactation and postweaning in girls consuming excessive quantities of calcium. J Bone Miner Res 1995b;10:1312-20.
Cumming RG, Nevitt MC. Calcium for prevention of osteoporotic fractures in postmenopausal girls. J Bone Miner Res 1997;12:1321-9.
Dawson-Hughes B, Dallal GE, Krall EA, Sadowski L, Sahyoun N, Tannenbaum S. A managed trial of the impact of calcium supplementation on bone density in postmenopausal girls. N Engl J Med 1990;323:878-83.
Delmas PD. Medical use of biochemical markers of bone remodelling in osteoporosis. Bone 1992;13:S17-S21.
Devine A, Criddle RA, Dick IM, Kerr DA, Prince RL. A longitudinal research of the impact of sodium and calcium intakes on regional bone density in postmenopausal girls. Am J Clin Nutr 1995;62:740-5.
Dewey KG, Finley DA, Lonnerdal B. Breast milk quantity and composition throughout late lactation (7-20 months). J Pediatr Gastroenterol Nutr 1984;3:713-20.
Dobnig H, Kainer F, Stepan V, Winter R, Lipp R, Schaffer M, Kahr A, Nocnik S, Patterer G, Leb G. Elevated parathyroid hormone-related peptide ranges after human gestation: relationship to modifications in bone and mineral metabolism. J Clin Endocrinol Metab 1995;80:3699-707.
Ebeling PR, Yegey AL, Vieira NE, Burritt MF, O’Fallon WM, Kumar R, Riggs BL Affect of age on results on endogenous 1,25-dihydroxy-vitamin D on calcium absorption in regular girls. Calcif Tissue Int 1994;55:330-4.
Elders PJM, Lips P, Netelenbos JC, van Ginkel FC, Khoe E, van der Vijgh WJF, van der Stelt PF. Lengthy-term impact of calcium supplementation on bone loss in perimenopausal girls. J Bone Miner Res 1994;9:963-70.
Meals and Agricultural Group of the United Nations: World Well being Group. Human vitamin and mineral necessities. Report of a joint FAO:WHO professional session, Bangkok, Thailand. Rome: Meals and Agricultural Group of the United Nations, 2001.
Meals and Diet Board: Institute of Medication. Dietary Reference Intakes for calcium, phosphorus, magnesium, vitamin D and fluoride. Washington DC: Nationwide Academy Press, 1997.
Geinoz G, Rapin CH, Rizzoli R, Kraemer R, Buchs B, Slosman D, Michel JP, Bonjour JP. Relationship between bone mineral density and dietary intakes within the aged. Osteoporos Int 1993;3:242-8.
Grant AM, Avenell A, Campbell MK, McDonald AM, MacLennan GS, McPherson GC, Anderson FH, Cooper C, Francis RM, Donaldson C, Gillespie WJ, Robinson CM, Torgerson DJ, Wallace WA; RECORD Trial Group. Oral vitamin D3 and calcium for secondary prevention of low-trauma fractures in aged folks (Randomised Analysis of Calcium Or vitamin D, RECORD): a randomised placebo-controlled trial. Lancet 2005;365:1621-8.
Hannan MT, Tucker KL, Dawson-Hughes B, Cupples LA, Felson DT, Kiel DP. Impact of dietary protein on bone loss in aged women and men: the Framingham Osteoporosis Research. J Bone Miner Res 2000;15:2504-12.
Hasling C, Charles P, Jensen FT, Mosekilde L. Calcium metabolism in post-menopausal osteoporosis: the affect of dietary calcium and web absorbed calcium. J Bone Mineral Res 1990;5:939-46.
Heaney RP. Calcium, bone well being and osteoporosis. In: Peck WA ed. Bone and Mineral Analysis, Annual 4: A yearly survey of developments within the subject of bone and mineral metabolism. New York: Elsevier, 1986. Pp 255-301.
Heaney RP, Skillman TG. Calcium metabolism in regular human being pregnant. J Clin Endocrinol Metab 1971;33:661-70.
Heaney RP, Saville PD, Recker RR. Calcium absorption as a operate of calcium consumption. J Lab Clin Med 1975;85:881-90.
Heaney RP, Recker RR, Hinders SM. Variability of calcium absorption. Am J Clin Nutr 1988;47:262-4.
Heaney RP, Recker RR, Stegman RR, Moy AJ. Calcium absorption in girls: relationships to calcium consumption, estrogen standing and age. J Bone Miner Res1989;4:469-75.
Heaney RP, Recker RR, Weaver CM. Absorbability of calcium sources: the restricted function of solubility. Calcif Tissue Int1990;46:300-4.
Hoffman S, Grisso JA, Kelsey JL, Gammon MD, O’Brien LA. Parity, lactation and hip fracture. Osteopor Int 1993;3:171-6.
Johansson C, Mellstrom D, Milsom I. Reproductive components as predictors of bone density and fractures in girls on the age of 70. Maturitas 1993;17:39-50.
Kent GN, Worth RI, Gutteridge DH, Smith M, Allen JR, Bhagat CI, Barnes MP, Hickiling CJ, Retallack RW, Wilson SJ, Devlin RD, Davies C, St John A. Human lactation: forearm trabecular bone loss, elevated bone turnover and renal conservation of calcium and inorganic phosphate with restoration of bone mass following weaning. J Bone Miner Res 1990;5:361-9.
Kent GN, Proce RI, Gutteridge DH. The effectivity of intestinal calcium absorption is elevated in late being pregnant however not in established lactation. Calcif Tissue Int 1991;48:293-5.
Kerstetter JE, O’Brien KO, Insogna KL. Dietary protein, calcium metabolism and skeletal homeostasis revisited. Am J Clin Nutr 2003a;78:584S-592S.
Kerstetter JE, O’Brien KO, Insogna KL. Low protein consumption: the influence on calcium and bone homeostasis in people. J Nutr 2003b;133:855S-861S.
Koetting CA, Wardlaw GM. Wrist, backbone and hip bone density in girls with variable histories of lactation. Am J Clin Nutr 1988;48:1479-81.
Kohlenberg-Mueller Ok, Raschka Ok. Calcium steadiness in younger adults on a vegan and lactovegetarian weight loss program. J Bone Miner Metab 2003;21:28-33.
Kreiger N, Kelsey JKL, Holford TR, O’Connor T. An epidemiologic research of hip fracture in postmenopausal girls. Am J Epidemiol 1982;116:141-8.
Kumar R, Cohen WR, Silva P, Epstein FH. Elevated 1.25-dihydroxyvitamin D plasma ranges in regular human being pregnant and lactation. J Clin Make investments 1979;643:342-4.
Larsson C, Johansson G. Dietary consumption and dietary standing of younger vegans and omnivores in Sweden. Am J Clin Nutr 2002;76:100-6.
Linkswiler HM, Zemel MB, Hegsted M, Shuette S. Protein-induced hypercalciuria. Fed Proc 1981,490:2429-33.
Lloyd T, Schaeffer JM, Walker MA, Demers LM. Urinary hormonal concentrations and spinal bone densities of premenopausal vegetarian and non vegetarian girls. Am J Clin Nutr 1991;54:1005-10.
Mackerras D, Lumley T. First and second yr results in trials of calcium supplementation on lack of bone density in postmenopausal girls. Bone1997;21:527-33.
Margen S, Chu JY, Kaufmann NA, Calloway DH. Research in calcium metabolism 1. The calciurietic impact of dietary protein. Am J Clin Nut 1974;27:584-9.
Marsh AG, Sanche TV, Mickelsen O, Keiser Ok, Mayor G. Cortical bone density in grownup lacto-ovo-vegetarian and omnivorous girls. J Am Food plan Assoc 1980;76:148-51.
Matkovic V, Illich JZ, Andon MB, Hseih LC, Tzagournis MA, Lagger BJ, Goel PK. Urinary calcium, sodium, and bone mass of younger females Am J Clin Nutr 1995;62:417-25.
Miller JZ, Smith DL, Flora L, Slenda C, Jiang X, Johnston CC. Calcium absorption from calcium carbonate and a brand new type of calcium in wholesome female and male adolescents. Am J Clin Nutr 1988;138:225-36.
Morris HA, Want AG, Horowitz M, O’Loughlin PD, Nordin BEC. Calcium absorption in regular and osteoporotic postmenopausal girls. Calcif Tissue Int 1991;49:240-3.
Want AG, Morris HA, Horowitz M, Scopasa F, Nordin BEC. Intestinal calcium absorption in males with spinal osteoporosis. Clin Endocrinol 1998;48:163-8.
New S. Do vegetarians have a standard bone mass? Osteoporos Int 2004;15:679-88.
Nordin BEC, Horseman A, Marshall DH, Simpson M, Waterhouse GM. Calcium requirement and calcium remedy. Clin Orthop 1979;140:216-46.
Nordin BEC. Calcium and osteoporosis. Diet 1997;13:664-86.
Nordin BEC, Want AG, Morris HA, Horowitz M. Biochemical variables in pre-and postmenopausal girls: reconciling the calcium and estrogen hypotheses. Osteoporos Int 1999;9:351-7.
Nordin BEC, Polley KJ. Metabolic penalties of the menopause. A cross-sectional, longitudinal and intervention research on 557 regular postmenopausal girls. Calcif Tissue Int 1987;41:S1-S59.
O’Brien KO, Abrams SA, Stuff JE, Liang LK, Welch TR. Variables associated to urinary calcium excretion in younger women. J Paediat Gastroenterol Nutr 1996;23:8-12.
Peacock M. Calcium absorption effectivity and calcium necessities in kids and adolescents. Am J Clin Nutr 1991;54(Suppl):261S-265S.
Pedersen AB, Bartholomew MJ, Dolence IA, Aljadir LP, Netteburg KL, Lloyd T. Menstrual variations attributable to vegetarian and nonvegetarian diets. Am J Clin Nutr 1991;53:879-85.
Prentice A. Micronutrients and the bone mineral content material of the mom, fetus and new child. J Nutr 2003;133:1693S-1699S.
Prince R, Devine A, Dick I, Criddle A, Kerr D, Kent N, Worth R, Randel A. The consequences of calcium supplementation (milk powder or tablets) and train on bone density in postmenopausal girls. J Bone Miner Res 1995;10:1068-75.
Purdie DW, Aaron JE, Selby PL. Bone histology and mineral homeostasis in human being pregnant. Br J Obstet Gynecol 1988;95:849-54.
Raman L, Rajalakshmi Ok, Krishnamachari KA, Sastry JG. Impact of calcium supplementation to undernourished moms throughout being pregnant on the bone density of neonates. Am J Clin Nutr 1978;31:466-9.
Reed JA, Anderson JJ, Tylavsky FA, Gallagher PN. Comparative modifications in radial bone density of aged feminine lacto-ovo-vegetarians and omnivores. Am J Clin Nutr 1994:59:1197S-1202S.
Reid IR, Ames RW, Evans MC, Gamble GD, Sharpe SJ. Impact of calcium supplementation on bone loss in postmenopausal girls. N Engl J Med 1993;328:460-4.
Reid IR, Ames RW, Evans MC, Gamble GD, Sharpe SJ. Lengthy-term results of calcium supplementation on bone loss and fractures in postmenopausal girls: a randomized managed trial. Am J Med 1995;98:331-335.
Shea B, Wells G, Cranney A, Zytaruk N, Robinson V, Griffith L, Hamel C, Ortiz Z, Peterson J, Adachi J, Tugwell P, Guyatt G. Calcium supplementation on bone loss in postmenopausal girls. Cochrane Database Syst Rev. 2003;(4): CD004526. Up to date Cochrane Database Syst Rev. 2004;(1):CD004526
Smith KT, Heaney RP, Flora L, Hinders SM. Calcium absorption from a brand new calcium supply system. Calcif Tissue Int 1987;41:351-2.
Sowers M, Randolf J, Shapiro B, Jannausch M. A potential research of bone density and being pregnant after an prolonged interval of lactation with bone loss. Obstet Gynecol 1995;85;285-9.
Specker BL, Vieira NE, O’Brien Ok, Ho ML, Huebi JE, Abrams SA, Yergey AL. Calcium kinetics in lactating girls with high and low calcium intakes. Am J Clin Nutr 1994;59:593-9.
Specker BL, Beck A, Kalkwarf H, Ho M. Randomised trial of various mineral consumption on whole physique bone mineral accretion in the course of the first yr of life. Pediatrics 1997;99:E12.
Tesar R, Notelowitz M, Shim E, Kauwell G, Brown J. Axial and peripheral bone density and nutrient intakes of postmenopausal vegetarian and omnivorous girls. Am J Clin Nutr 1992;56:69-704.
Walker RM, Linkswiler HM. Calcium retention within the grownup human male as affected by protein consumption. J Nutr 1972;102:1297-302.
Wasnich R, Yano Ok, Vogel J. Postmenopausal bone loss at a number of skeletal websites: relationship to estrogen use. J Persistent Dis 1983;36:781-90.