Calcium supplementation from low fat dairy products or calcium supplements is a good idea for children, teens, and women of all ages, but probably a bad idea for men past the age of 35, as it is associated with an increased risk of prostate cancer and possible Parkinson's disease in men only.
For adult women, I recommend the combination of calcium 500 mg, magnesium 250 mg, and vitamin D 200 units twice a day. An added 1000 units of vitamin D is good for everyone, including men, for whom I recommend the magnesium without the calcium.
Cancer: Endometrial: Vitamin D and Calcium Lower Risk: In a case-control study of 85 cases of endometrial cancer and 629 controls, there was no association between EC risk and consumption of animal or vegetable proteins, saturated, monounsaturated, or polyunsaturated fat, although high intake of lactose (odds ratio [OR], 0.46, P = 0.004), vitamin D (OR, 0.38, P= 0.003), and calcium (OR, 0.39, P= 0.02) were inversely associated with EC. Dietary vitamin D and calcium may play an important role in the development of EC. Dietary factors and endometrial cancer risk. Results of a case-control study in Mexico. Salazar-Martinez E, et al. National Institute of Public Health, Cuernavaca, Mexico. Int J Gynecol Cancer. 2005 Sep-Oct;15(5):938-45.
Calcium and Vitamin D No Impact on Colon Cancer in Huge Study: In a 7-year DB PC study of 36,282 postmenopausal women, 1000 mg of elemental calcium and 400 IU of vitamin D3 had no impact on the number of cases of invasive colon cancer (168 vs. 154 for placebo). Calcium plus vitamin D supplementation and the risk of colorectal cancer. There was a non-significant 12% decrease in hip and 10% decrease in spinal fractures. Wactawski-Wende J, et al. University at Buffalo. . New Eng J Med 2006 Feb 16;354(7):684-96.
Height: Calcium Supplement Increases Skeletal Growth and Height in Teenage Boys: In a 13-month DB PC study of 143 boys ages 16-18, those taking calcium 1000 mg/d developed greater bone mineral content (BMC) of the whole-body (+1.3%, P = 0.02), lumbar spine (+2.5%, P = 0.004) and hip (total +2.3%, P = 0.01; neck +2.4%, P = 0.02; intertrochanter +2.7%, P = 0.01). This was associated with greater height (+0.4%, P = 0.0004, equivalent to 7 mm or over 1/4 inch), lean mass (+1.3%, P = 0.02) and lumbar spine bone area (+1.5%, P = 0.003). The increases in BMC diminished after size adjustment, suggesting that the intervention effect was mediated through an effect on growth. The BMC response at the intertrochanter was greater in subjects with high physical activity (+4.4%, P = 0.05). Calcium supplementation increases stature and bone mineral mass of 16-18 year old boys. Prentice A, Ginty F, et al. Institute of Child Health, London, UK. J Clin Endocrinol Metab. 2005 Mar 8
Metabolic Syndrome Reduced with Higher Calcium Intake: Using data from 10,066 women over age 44 from the Women's Health Study who were free of cardiovascular disease, cancer, or diabetes and who never used postmenopausal hormones, in age- and calorie-adjusted analyses, higher intakes of total, dietary, and supplemental calcium were significantly and inversely associated with the prevalence of metabolic syndrome. After further adjusting for smoking status, exercise, alcohol intake, multivitamin use, and parental history of myocardial infarction before age 60 years, the ORs of having the metabolic syndrome for increasing quintiles of total calcium intake were 1.00 (reference), 0.82, 0.84, 0.70, and 0.64 (P for trend <0.0001). This association was not appreciably altered by additional adjustment for other dietary factors or total vitamin D intake. Neither total (P for trend = 0.13) nor supplemental (P = 0.45) vitamin D was significantly associated with metabolic syndrome. Dietary calcium, vitamin D, and the prevalence of metabolic syndrome in middle-aged and older U.S. women. Liu S, et al. Brigham and Women's-Harvard. . Diabetes Care 2005 Dec;28(12):2926-32. Ed: Vitamin D at higher doses, e.g. 1000-2000 units/day, does have a beneficial effect.
Obesity: High Intake Lowers Obesity in Mice and Humans: Increasing adipocyte intracellular Ca(2+) results in a coordinated stimulation of lipogenesis and inhibition of lipolysis. However, increasing dietary calcium of obese patients for 1 year resulted in an 11 pound loss of body fat (P<0.01). Calcitrophic hormones act on adipocytes to increase Ca(2+) and lipid metabolism. 1, 25-(OH)(2)-D in cultures of human adipocytes cause sustained increases in intracellular Ca(2+) and a corresponding marked inhibition of lipolysis (P<0.001). In mice, weight gain and fat pad mass were reduced by 26-39% by the three high calcium diets (P<0.001). The high calcium diets exerted a corresponding 51% inhibition of adipocyte fatty acid synthase expression and activity (P<0.002) and stimulation of lipolysis by 430% (P<0.015). This concept of calcium modulation of adiposity was further evaluated epidemiologically in the NHANES III data set. After controlling for energy intake, relative risk of being in the highest quartile of body fat was set to 1.00 for the lowest quartile of Ca intake and was reduced to 0.75, 0.40, and 0.16 for the second, third, and fourth quartiles, respectively, of calcium intake for women (n=380;P<0.0009); a similar inverse relationship was also noted in men (n=7114; P<0.0006). Univ Tennessee. Regulation of adiposity by dietary calcium. Zemel MB, Shi H, Greer B, Dirienzo D, Zemel PC. FASEB J. 2000 Jun;14(9):1132-8
Obese Have Higher Bone Density and Fewer Fractures: In a Japanese study of 93 women, the incidence of vertebral fracture was found to be negatively correlated with BMI (the incidences of vertebral fracture in slender, normal and obese were 78.6, 48.8 and 22.7%, respectively) and bone mineral density was also BMI-related (0.390, 0.456 and 0.493 g/cm2). The number of years after menopause was shorter in patients with a higher BMI. There was no intergroup difference in serum levels of PTH, vitamin D and estrogens. On the other hand, serum levels of calcitonin, DHEA, DHEAS, delta-4 androstenedione and testosterone were found to be higher in subjects with a higher BMI. Bone mineral density is supported not only by weight-bearing stress upon bone, but also by serum levels of calcitonin and androgens in obese females. Relation between body size and bone mineral density with special reference to sex hormones and calcium regulating hormones in elderly females. Shiraki M, Ito H, Fujimaki H, Higuchi T. Endocrinol Jpn. 1991 Aug;38(4):343-9
Obesity: Supplement During Weight Loss Helps Protect Female Bones: Weight loss (WL) reduces bone mass and increases fracture risk. In a study of 73 overweight women put on a weight loss diet or their standard diet and receiving high or normal calcium in the DB manner, those losing weight and taking normal amounts of calcium had decreased absorption and inadequate calcium supplies with some activation of parathyroid hormone secretion and probable resorption of calcium from bone. Those on the calcium supplement had decrease absorption, but the extra calcium maintained adequate levels to protect bone mass. Weight loss and calcium intake influence calcium absorption in overweight postmenopausal women. Cifuentes M, Riedt CS, Brolin RE, Field MP, Sherrell RM, Shapses SA. Rutgers University. Am J Clin Nutr. 2004 Jul;80(1):123-30
Osteoporosis: Calcium, Tea Good; Late Menarche, Low Exercise & Low Sunlight Bad: A low BMI and milk consumption were significant risks only in the lowest 50% and 10% of the population, respectively. A late menarche, poor mental score, low BMI and physical activity, low exposure to sunlight, and a low consumption of calcium and tea remained independent risk factors after multivariate analysis, accounting for 70% of hip fractures. Excluding mental score and age at menarche (not potentially reversible), the attributable risk was 56%. Risk factors for hip fracture in European women: the MEDOS Study. Mediterranean Osteoporosis Study. Johnell O, Gullberg B, Kanis JA, Allander E, Elffors L, Dequeker J, Dilsen G, Gennari C, Lopes Vaz A, Lyritis G, et al. J Bone Miner Res. 1995 Nov;10(11):1802-15; But, In both men and women, the adjusted intakes of protein, saturated fatty acids, vitamin D, magnesium, and phosphorus were significantly higher in the high-calcium-intake group of 957 at UCSD. Am J Clin Nutr. 1991 Mar;53(3):741-4
Osteoporosis: Vitamin D Plus Calcium Helps Fracture Healing in Elderly: In a 12-week DB PC study of 30 elderly women average age 78 with humerus fractures, those receiving oral 800 IU vitamin D(3) plus 1 g calcium had a positive effect on fracture healing over the first 6 weeks. The Effect of Calcium and Vitamin D(3) Supplementation on the Healing of the Proximal Humerus Fracture: A Randomized Placebo-Controlled Study. Doetsch AM, Faber J, Lynnerup N, Watjen I, Bliddal H, Danneskiold-Samsoe B. Frederiksberg Hospital, Copenhagen, Denmark. Calcif Tissue Int. 2004 May 27
Osteoporosis: Vitamin D 400 IU with Calcium 500 Helps Deficient Women: DB PC 12 mo. 192 65+yos. Effects on bone mineral density of calcium and vitamin D supplementation in elderly women with vitamin D deficiency. Grados F, Brazier M, Kamel S, Duver S, Heurtebize N, Maamer M, Mathieu M, Garabedian M, Sebert JL, Fardellone P. Joint Bone Spine. 2003 Jun;70(3):203-8
Osteoporosis: Vitamin D 10,000 IU/wk No Benefit on 1000mg Calcium: In a 2-year DB PC study of women with an average age of 56, there was no statistically significant difference between those on calcium alone or calcium and vitamin D. Am J Clin Nutr. 2003 May;77(5):1324-9
Osteoporosis: Seasonal Bone Loss Reversed by Vitamin D and Calcium: In a random-assignment open study of 55 adults, half were given 500 IU oral vitamin D(3) and calcium 500 mg/day during the winter months. Before the supplement, both groups lost bone during the winter months. In the year of supplementation, the vitamin D group gained 0.3-0.9% lumbar and femoral bone while the control group continued to lose bone. Supplementation with oral vitamin d3 and calcium during winter prevents seasonal bone loss: a randomized controlled open-label prospective trial. Meier C, Woitge HW, Witte K, Lemmer B, Seibel MJ. University Sydney.
Thomas E. Radecki, M.D., J.D.