Calcium Magnesium Supplement

Calcium, vitamin D, dairy products, and risk of colorectal cancer in the cancer prevention study II nutrition cohort (United States).

McCullough ML, Robertson AS, Rodriguez C, Jacobs EJ, Chao A, Carolyn J, Calle EE, Willett WC, Thun MJ.

Epidemiology and Surveillance Research Department, American Cancer Society, 1599 Clifton Rd NE, Atlanta GA, 30309 USA.

OBJECTIVE: Calcium, vitamin D, and dairy product intake may reduce the risk of colorectal cancer. We therefore examined the association between these factors and risk of colorectal cancer in a large prospective cohort of United States men and women. METHODS: Participants in the Cancer Prevention Study II Nutrition Cohort completed a detailed questionnaire on diet, medical history, and lifestyle in 1992-93. After excluding participants with a history of cancer or incomplete dietary information, 60,866 men and 66,883 women remained for analysis. During follow-up through 31 August 1997 we documented 421 and 262 cases of incident colorectal cancers among men and women, respectively. Multivariate-adjusted rate ratios (RR) were calculated using Cox proportional hazards models. RESULTS: Total calcium intake (from diet and supplements) was associated with marginally lower colorectal cancer risk in men and women (RR = 0.87, 95% CI 0.67-1.12, highest vs lowest quintiles, p trend = 0.02). The association was strongest for calcium from supplements (RR = 0.69, 95% CI 0.49-0.96 for > or = 500 mg/day vs none). Total vitamin D intake (from diet and multivitamins) was also inversely associated with risk of colorectal cancer, particularly among men (RR = 0.71, 95% CI 0.51-0.98, p trend = 0.02). Dairy product intake was not related to overall risk. CONCLUSIONS: Our results support the hypothesis that calcium modestly reduces risk of colorectal cancer. Vitamin D was associated with reduced risk of colorectal cancer only in men.

J Womens Health (Larchmt). 2003 Mar;12(2):173-82.

Diet, body weight, and colorectal cancer: a summary of the epidemiologic evidence.

Giovannucci E.

Channing Laboratory, Department of Medicine, Brigham and Women's Hospital, Boston, Massachusetts 02115, USA. edward.giovannucci@channing.harvard.edu

Colorectal cancer is the second leading cause of cancer death in the United States, and the number of new cases annually is approximately equal for men and women. Several nutritional factors are likely to have a major influence on risk of this cancer. Physical inactivity and excessive adiposity, especially if centrally distributed, clearly increase the risk of colon cancer. Hyperinsulinemia may be an important underlying risk factor. In conjunction with obesity and physical inactivity, which induce a state of insulin resistance, certain dietary patterns that stimulate insulin secretion, including high intakes of red and processed meats, saturated and trans-fats, and highly processed carbohydrates and sugars, may increase the risk of colon cancer. There is evidence suggesting that some component of red meat may independently increase the risk of colorectal cancer, and some micronutrients may be important as protective agents. Currently, the evidence is strongest for folate and calcium. Folate may be especially important in alcohol drinkers because alcohol appears to increase the risk, particularly when folate intake is low. This interaction may be related to the antifolate properties of alcohol. In contrast to earlier studies, more recent epidemiologic studies have generally not supported a strong influence of dietary fiber or fruits and vegetables, although these have other health benefits, and their consumption should be encouraged. The majority of colon cancers, as well as many other conditions, may be prevented by lifestyle alterations in the intake of these nutritional factors, in addition to other factors, such as smoking.

Early development of cancer chemoprevention clinical trials: studies of dietary calcium as a chemopreventive agent for human subjects.

Lipkin M.

Strang Cancer Prevention Center and Weill Medical College of Cornell University, New York, NY 10021, USA. lipkin@mail.rockefeller.edu

Early cancer chemoprevention clinical trials in human subjects had to be carried out with large numbers of subjects studied for long durations, measuring cancer as an end point. However new findings on abnormal epithelial cell growth and development during the multistage evolution of colonic tumors made it possible to carry out chemoprevention clinical trials in several stages, with fewer subjects studied for shorter durations, thus enabling investigators to analyze increasing numbers of chemopreventive agents and nutritional regimens in clinical trials. Supplemental dietary calcium was the first candidate chemopreventive agent studied in this multistage approach in human subjects, as a putative agent for colon cancer prevention. Early- and late-stage intermediate biomarker studies in humans have strongly suggested utility for supplemental dietary calcium to inhibit the development of benign and subsequent malignant colonic neoplasms. Preclinical experimental studies have further demonstrated the ability of increased dietary calcium to inhibit the evolution of colonic tumors when they were induced by targeted mutations, dietary factors, and particularly when given over a long duration of lifespan.

Dietary influences on survival after ovarian cancer.

Nagle CM, Purdie DM, Webb PM, Green A, Harvey PW, Bain CJ.

School of Population Health, University of Queensland, Brisbane, Australia.

We evaluated the effects of various food groups and micronutrients in the diet on survival among women who originally participated in a population-based case-control study of ovarian cancer conducted across 3 Australian states between 1990 and 1993. This analysis included 609 women with invasive epithelial ovarian cancer, primarily because there was negligible mortality in women with borderline tumors. The women's usual diet was assessed using a validated food frequency questionnaire. Deaths in the cohort were identified using state-based cancer registries and the Australian National Death Index (NDI). Crude 5-year survival probabilities were estimated using the Kaplan-Meier technique, and adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) were obtained from Cox regression models. After adjusting for important confounding factors, a survival advantage was observed for those who reported higher intake of vegetables in general (HR = 0.75, 95% CI = 0.57-0.99, p-value trend 0.01 for the highest third, compared to the lowest third), and cruciferous vegetables in particular (HR = 0.75, 95% CI = 0.57-0.98, p-value trend 0.03), and among women in the upper third of intake of vitamin E (HR = 0.76, 95% CI = 0.58-1.01, p-value trend 0.04). Inverse associations were also seen with protein (p-value trend 0.09), red meat (p-value trend 0.06) and white meat (p-value trend 0.07), and modest positive trends (maximum 30% excess) with lactose (p-value trend 0.04), calcium and dairy products. Although much remains to be learned about the influence of nutritional factors after a diagnosis of ovarian cancer, our study suggests the possibility that a diet high in vegetable intake may help improve survival.

Am J Clin Nutr. 2003 Jun;77(6):1448-52.

Calcium intake, body composition, and lipoprotein-lipid concentrations in adults.

Jacqmain M, Doucet E, Despres JP, Bouchard C, Tremblay A.

Division of Kinesiology (MJ and AT) and the Department of Food Science and Nutrition (J-PD), Laval University, Ste-Foy, Quebec.

BACKGROUND: Recent data suggest that variations in calcium intake may influence lipid metabolism and body composition. OBJECTIVE: The association between daily calcium intake and body composition and plasma lipoprotein-lipid concentrations was studied cross-sectionally in adults from phase 2 of the Quebec Family Study. DESIGN: Adults aged 20-65 y (235 men, 235 women) were studied. Subjects who consumed vitamin or mineral supplements were excluded. Subjects were divided into 3 groups on the basis of their daily calcium intake: groups A (< 600 mg), B (600-1000 mg), and C (> 1000 mg). RESULTS: Daily calcium intake was negatively correlated with plasma LDL cholesterol, total cholesterol, and total:HDL cholesterol in women and men after adjustment for variations in body fat mass and waist circumference (P < 0.05). In women, a significantly greater ratio of total to HDL cholesterol (P < 0.05) was observed in group A than in group C after correction for body fat mass and waist circumference. In women, body weight, percentage body fat, fat mass, body mass index, waist circumference, and total abdominal adipose tissue area measured by computed tomography were significantly greater (P < 0.05) in group A than in groups B and C, even after adjustments for confounding variables. Comparable trends were observed in men, but not after adjustment for the same covariates. CONCLUSION: A low daily calcium intake is associated with greater adiposity, particularly in women. In both sexes, a high calcium intake is associated with a plasma lipoprotein-lipid profile predictive of a lower risk of coronary heart disease risk compared with a low calcium intake.

Steroid induced osteoporosis: prevention and treatment

[Article in French]

Roux C, Orcel P.

Institut de rhumatologie, hopital Cochin, centre d'evaluation des maladies osseuses, 27, rue du Faubourg-Saint-Jacques, 75014, Paris, France

Purpose. - Corticosteroid induced osteoporosis (CIO) is the most frequent complication of long-term corticosteroid therapy, and the most frequent cause of secondary osteoporosis. New data from biological, epidemiological and therapeutic studies provide basis for optimal management of this bone disease.Main points. - Corticosteroids are responsible for both quantitative and qualitative deleterious effects on bone, through their effect on bone cells, mainly on osteoblasts (with both a decrease in osteoblast activity and an increase in apoptosis). Epidemiological studies have shown an increased risk of fractures related to CIO, even for low doses, and during the first 6 months of treatment. Relative risk is 1.3 and 2.6 for peripheral and vertebral fractures respectively. Bone mineral density, measured by dual-energy X-ray absorptiometry, is decreased at spine and hip; the risk of fracture is higher in CIO as compared to post-menopausal osteoporosis, for a similar bone density. Prevention of CIO needs the use of the minimal efficacious dose, and treatment of calcium, vitamin D and gonadal hormones insufficiencies. Patients at risk of fracture, as post-menopausal women with prevalent fractures, should receive a bisphosphonate.Perspective. - It may be possible to reduce the fracture risk in patients on long-term corticosteroid therapy.

Joint Bone Spine. 2003 Jun;70(3):203-208.

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.

Rheumatology Department, North Hospital Group, 80054 cedex 1, Amiens, France

Objectives. - Calcium and vitamin D deficiency is common in older individuals, particularly those who live in nursing homes, and increases the risk of osteoporosis and fractures.Methods. - We conducted a randomized double-blind placebo-controlled study of combined supplementation with 500 mg of elemental calcium, as carbonate, and 400 IU of vitamin D bid for 12 months in women older than 65 years of age with vitamin D deficiency, defined as serum 25(OH)D concentrations </=12 ng/ml.Results. - Mean patient age was 75 +/- 7 years, and median daily dietary intakes of calcium and vitamin D were 697 mg and 66.8 IU in the supplemented group (n = 95) and 671 mg and 61.8 IU in the placebo group (n = 97). The median serum 25(OH)D level was 7.0 ng/ml in both groups, and the medial intact parathyroid hormone (PTHi) levels were 49 and 48 pg/ml in the supplemented and placebo groups, respectively. The median increase in serum 25(OH)D was 22.0 ng/ml in the supplemented group and 4 ng/ml in the placebo group (P < 0.0001), and the median PTHi decrease was 17 and 5 pg/ml, respectively (P < 0.0001). The median bone mineral density increase was significantly greater in the supplemented group than in the placebo group: +2.98% vs. -0.21% at L2-L4 (P = 0.0009), +1.19% and -0.83% at the femoral neck (P = 0.015), +0.86% and -0.56% at the trochanter (P = 0.015), and +0.99% and +0.11% for the whole body (P = 0.01). Similarly, the median decrease in the main bone markers was significantly greater in the treated group than in the placebo group: -1.35 &mgr;g/l vs. +0.50 &mgr;g/l for bone alkaline phosphatase (P = 0.008), -16.6 nmol/mmol creatinine vs. -2.3 nmol/mmol creatinine for urinary type I amino-terminal telopeptide (P = 0.001), and -896 pmol/l vs. -201 pmol/l for serum type I carboxy-terminal telopeptide (P = 0.003). We found no significant differences between the two groups for serum calcium, although urinary calcium excretion changed more in the supplemented group than in the placebo group. In conclusion, bone mass in older women with vitamin D deficiency increases significantly at the lumbar spine, femur, trochanter, and whole body after calcium and vitamin D supplementation for 1 year, and concomitantly bone markers improved as vitamin D levels returned to normal.

BMC Public Health. 2003 Jun 18 [Epub ahead of print].

The influence of calcium and magnesium in drinking water and diet on cardiovascular risk factors in individuals living in hard and soft water areas with differences in cardiovascular mortality.

Nerbrand C, Agreus L, Lenner RA, Nyberg P, Svardsudd K.

:BackgroundThe role of water hardness as a risk factor for cardiovascular disease has been widely investigated and evaluated as regards regional differences in cardiovascular disease. This study was performed to evaluate the relation between calcium and magnesium in drinking water and diet and risk factors for cardiovascular disease in individuals living in hard and soft water areas with considerable differences in cardiovascular mortality.MethodsA random sample of 207 individuals living in two municipalities characterised by differences in cardiovascular mortality and water hardness was invited for an examination including a questionnaire about health, social and living conditions and diet. Intake of magnesium and calcium was calculated from the diet questionnaire with special consideration to the use of local water. Household water samples were delivered by each individual and were analysed for magnesium and calcium.ResultsIn the total sample, there were positive correlations between the calcium content in household water and systolic blood pressure (SBP) and negative correlations with s-cholesterol and s-LDL-cholesterol. No correlation was seen with magnesium content in household water to any of the risk factors.Calcium content in diet showed no correlation to cardiovascular risk factors. Magnesium in diet was positively correlated to diastolic blood pressure (DBP). In regression analyses controlled for age and sex 18.5% of the variation in SBP was explained by the variation in BMI, HbA1c and calcium content in water. Some 27.9% of the variation in s-cholesterol could be explained by the variation in s-triglycerides (TG), and calcium content in water.ConclusionsThis study of individuals living in soft and hard water areas showed significant correlations between the content of calcium in water and major cardiovascular risk factors. This was not found for magnesium in water or calcium or magnesium in diet. Regression analyses indicated that calcium content in water could be a factor in the complexity of relationships and importance of cardiovascular risk factors. From these results it is not possible to conclude any definite causal relation and further research is needed.

S Afr Med J. 2003 Mar;93(3):224-8.

Calcium supplementation to prevent pre-eclampsia--a systematic review.

Hofmeyr GJ, Roodt A, Atallah AN, Duley L.

Effective Care Research Unit, East London Hospital Complex, University of the Witwatersrand, Johannesburg/Fort Hare University, East London, E Cape.

BACKGROUND: Calcium supplementation during pregnancy may prevent high blood pressure and preterm labour. OBJECTIVE: To assess the effects of calcium supplementation during pregnancy on hypertensive disorders of pregnancy and related maternal and child adverse outcomes. DESIGN: A systematic review of randomised trials that compared supplementation with at least 1 g calcium daily during pregnancy with placebo. SEARCH STRATEGY: The Cochrane Pregnancy and Childbirth Group trials register (October 2001) and the Cochrane Controlled Trials Register (Issue 3, 2001) were searched and study authors were contacted. DATA COLLECTION AND ANALYSIS: Eligibility and trial quality were assessed. Data were extracted and analysed. MAIN RESULTS: There was a modest reduction in the risk of pre-eclampsia with calcium supplementation (relative risk (RR) 0.68, 95% confidence interval (CI): 0.57-0.81). The effect was greatest for women at high risk of hypertension (RR 0.21, 95% CI: 0.11-0.39) and those with low baseline calcium intake (RR 0.32, 95% CI: 0.21-0.49). There was no overall effect on the risk of preterm delivery, although there was a reduction in risk among women at high risk of hypertension (RR 0.42, 95% CI: 0.23-0.78). There was no evidence of any effect of calcium supplementation on stillbirth or death before discharge from hospital. There were fewer babies with birthweight < 2,500 g (RR 0.83, 95% CI: 0.71-0.98). In one study, childhood systolic blood pressure > 95th percentile was reduced (RR 0.59, 95% CI: 0.39-0.91). CONCLUSIONS: Calcium supplementation appears to be beneficial for women at high risk of gestational hypertension and in communities with low dietary calcium intake. These benefits were confined to several rather small trials, and were not found in the largest trial to date, conducted in a low-risk population. Further research is required.

Adv Neurol. 2003;92:173-8.

Nutritional and metabolic aspects of stroke prevention.

Spence JD.

Department of Clinical Neurological Sciences, University of Western Ontario, Stroke Prevention and Atherosclerosis Research Centre, Robarts Research Institute, London, Ontario, Canada.

Epidemiologic evidence, animal studies, angiographic and ultrasound studies in humans, and a limited number of clinical trials suggest that vitamins C and E may be protective and that folate, B6, and B12, by lowering homocysteine levels, may reduce stroke. However, these hypotheses require testing before widespread use of supplementary vitamins can be generally recommended (62). Clinical trials under way will test those hypotheses. In the meantime, it should be understood that the role of diet is much more important than is widely recognized. A diet low in saturated fat and cholesterol, low in sodium, high in potassium and calcium, and containing a lot of fruits and vegetables reduces blood pressure as much as an antihypertensive drug and in coronary patients is twice as effective as statin drugs in reducing death and myocardial infarction. Such a diet can therefore be confidently recommended as a source not only of natural proportions of vitamins and antioxidants but also for benefits that we are only beginning to define.

Maturitas. 2003 Apr 25;44(4):299-305.

Calcium-vitamin D3 supplementation is cost-effective in hip fractures prevention.

Lilliu H, Pamphile R, Chapuy MC, Schulten J, Arlot M, Meunier PJ.

CLP-Sante, 9-11 rue du Mont Aigoual, F-75015 Paris, France. herve.lilliu@clp-sante.fr

OBJECTIVE: To assess the cost implications for a preventive treatment strategy for institutionalised elderly women with a combined 1200 mg/day calcium and 800 IU/day vitamin D(3) supplementation in seven European countries. DESIGN: Retrospective cost effectiveness analysis based on a prospective placebo-controlled randomised clinical trial. DATA SOURCES: Recently published cost studies in seven European countries. Clinical results from Decalyos, a 3-year placebo-controlled study in elderly institutionalised women. TRIALS: Decalyos study, with 36 months follow-up of 3270 mobile elderly women living in 180 nursing homes, allocated to two groups. One group received 1200 mg/day elemental calcium in the form of tricalcium phosphate together with 800 IU/day (20 microg) of cholecalciferol (vitamin D(3)), the other placebo. RESULTS: In the 36 months analysis of the Decalyos study, 138 hip fractures occurred in the group of 1176 women, receiving supplementation and 184 hip fractures in the placebo group of 1127 women. The mean duration of treatment was 625.4 days. Adjusted to 1000 women, 46 hip fractures were avoided by the calcium and vitamin D(3) supplementation. For all countries, the total costs in the placebo group were higher than in the group receiving supplementation, resulting in a net benefit of 79000-711000 per 1000 women. CONCLUSION: This analysis suggests that the supplementation strategy is cost saving. The results may underestimate the net benefits, as this treatment has also shown to be effective in decreasing the incidence of other non-vertebral fractures in elderly institutionalised women.

J Hum Nutr Diet. 2003 Apr;16(2):97-109.

Nutritional management of rheumatoid arthritis: a review of the evidence.

Rennie KL, Hughes J, Lang R, Jebb SA.

MRC Human Nutrition Research, Elsie Widdowson Laboratory, Fulbourn Road, Cambridge, UK; Independent Nutrition Consultant, 7 Holmesdale Park, Nutfield, Surrey, UK.

Rheumatoid arthritis (RA) is a debilitating disease and is associated with increased risk of cardiovascular disease and osteoporosis. Poor nutrient status in RA patients has been reported and some drug therapies, such as nonsteroidal anti-inflammatory drugs (NSAIDs), prescribed to alleviate RA symptoms, may increase the requirement for some nutrients and reduce their absorption. This paper reviews the scientific evidence for the role of diet and nutrient supplementation in the management of RA, by alleviating symptoms, decreasing progression of the disease or by reducing the reliance on, or combating the side-effects of, NSAIDs. Supplementation with long-chain n-3 polyunsaturated fatty acids (PUFA) consistently demonstrates an improvement in symptoms and a reduction in NSAID usage. Evidence relating to other fatty acids, antioxidants, zinc, iron, folate, other B vitamins, calcium, vitamin D and fluoride are also considered. The present evidence suggests that RA patients should consume a balanced diet rich in long-chain n-3 PUFA and antioxidants. More randomized long-term studies are needed to provide evidence for the benefits of specific nutritional supplementation and to determine optimum intake, particularly for n-3 PUFA and antioxidants.

Can Fam Physician. 2002 Nov;48:1789-97.

Premenstrual syndrome. Evidence-based treatment in family practice.

Douglas S.

Department of Family Medicine, Dalhousie University, Abbie Lane Bldg, QEII Hospital, 5909 Veterans Memorial Ln, Halifax, NS B3H 2E2. sue.douglas@dal.ca

OBJECTIVE: To evaluate the strength of evidence for treatments for premenstrual syndrome (PMS) and to derive a set of practical guidelines for managing PMS in family practice. QUALITY OF EVIDENCE: An advanced MEDLINE search was conducted from January 1990 to December 2001. The Cochrane Library and personal contacts were also used. Quality of evidence in studies ranged from level I to level III, depending on the intervention. MAIN MESSAGE: Good scientific evidence shows that calcium carbonate (1200 mg/d) and selective serotonin reuptake inhibitors are effective treatments for PMS. The most commonly used therapies (including vitamin B6, evening primrose oil, and oral contraceptives) are based on inconclusive evidence. Other treatments for which there is inconclusive evidence include aerobic exercise, stress reduction, cognitive therapy, spironolactone, magnesium, nonsteroidal anti-inflammatory drugs, various hormonal regimens, and a complex carbohydrate-rich diet. Although evidence for them is inconclusive, it is reasonable to recommend healthy lifestyle changes given their overall health benefits. Progesterone and bromocriptine, which are still widely used, are ineffective. CONCLUSION: Calcium carbonate should be recommended as first-line therapy for women with mild-to-moderate PMS. Selective serotonin reuptake inhibitors can be considered as first-line therapy for women with severe affective symptoms and for women with milder symptoms who have failed to respond to other therapies. Other therapies may be tried if these measures fail to provide adequate relief.

Panminerva Med. 2001 Sep;43(3):177-209.

Hypomagnesemia. A review of pathophysiological, clinical and therapeutical aspects.

Iannello S, Belfiore F.

Institute of Internal Medicine and Internal Specialties, Chair of Internal Medicine, University of Catania Medical School, Garibaldi Hospital, Catania, Italy. francesco.belfiore@iol.it

The aim of this paper is to discuss, on the basis of an extensive literature review, the role of magnesium (Mg) in health and disease. Mg is an essential cation playing a crucial role in many enzyme systems. Quantitative Mg body stores are regulated by metabolic and hormonal effects on gastrointestinal absorption and renal excretion. Mg is a smooth muscle relaxant, dilates coronary arteries and peripheral vessels, exerts antiarrhythmic effects, may have a permissive effect on catecholamine actions and can play a role in various thrombogenic conditions. Today, hypomagnesemia has become a recognized medical occurrence which may be associated with many different diseases, either genetic or acquired. Mg deficiency is one of the most frequent electrolyte abnormalities in clinical practice, but it is probably the most underdiagnosed one. Clinical manifestations of hypomagnesemia may begin insidiously or dramatically sudden. A large part of the population (especially aged subjects) may have an inadequate Mg intake and a chronic latent Mg deficiency. Routine inclusion of serum Mg analysis in the electrolyte panel represents a continued need to recognize hypomagnesemia and to treat Mg-depleted patients. New clinical studies on Mg deficiency are necessary to ascertain the usefulness and cost-effectiveness of Mg replacement therapy.

South Med J. 2001 Dec;94(12):1195-201.

Comment in:
• South Med J. 2003 Jan;96(1):104.

Magnesium: its proven and potential clinical significance.

Fox C, Ramsoomair D, Carter C.

Department of Family Medicine, State University of New York at Buffalo, 14215, USA.

Magnesium is the fourth most abundant cation in the body and is present in more than 300 enzymatic systems, where it is crucial for adenosine triphosphate (ATP) metabolism. Deficiency states result in increased insulin resistance, as well as increased smooth muscle and platelet reactivity. Magnesium deficiency has been shown to correlate with a number of chronic cardiovascular diseases, including hypertension, diabetes mellitus, and hyperlipidemia. Intravenous magnesium has been used therapeutically in critical situations such as status asthmaticus, torsades de pointes, and preeclampsia. Few controlled studies exist regarding the therapeutic uses of oral magnesium supplementation in chronic cardiovascular diseases. Randomized clinical trials are urgently needed to determine whether magnesium supplementation will alter the natural history of these disease states.

Postgrad Med. 1992 Oct;92(5):217-9, 222-4.

Magnesium deficiency and diabetes mellitus. Causes and effects.

Rude RK.

University of Southern California School of Medicine, Los Angeles 90033.

A large body of evidence demonstrates the prevalence and adverse clinical consequences of magnesium deficiency in patients with diabetes mellitus. It would be prudent for physicians who treat these patients to consider magnesium deficiency as a contributing factor in many diabetic complications and in exacerbation of the disease itself. Repletion of the deficiency or prophylactic supplementation with oral magnesium may help avoid or ameliorate such complications as arrhythmias, hypertension, and sudden cardiac death and may even improve the course of the diabetic condition.

J Cardiovasc Nurs. 1993 Oct;8(1):19-31.

Magnesium in congestive heart failure, acute myocardial infarction and dysrhythmias.

Hix CD.

Hackettstown Community Hospital, New Jersey.

Magnesium plays an important role in the functioning of the cardiovascular system. A decrease in magnesium has been linked with tachydysrhythmias, increased mortality in patients with congestive heart failure, and increased mortality after an acute myocardial infarction. The research shows that the use of magnesium supplements in these situations may be beneficial for treating and preventing life-threatening conditions. Magnesium supplements can be administered safely either orally or parenterally depending on the situation.

New Horiz. 1994 May;2(2):186-92.

Should we supplement magnesium in critically ill patients?

Olerich MA, Rude RK.

Department of Diabetes, Los Angeles County/University of Southern California Medical Center 90033.

Magnesium (Mg) deficiency is a common yet underdiagnosed problem in the ICU. Since only 1% of total body Mg is in the extracellular fluid, serum Mg concentrations may not adequately reflect Mg status. Utilizing techniques to measure intracellular Mg concentrations, Mg depletion has been shown to be present in about one half of all ICU patients. These patients have significantly higher morbidity and mortality rates than Mg-replete patients. Accurate identification of patients with Mg depletion requires a knowledge of the risk factors associated with Mg deficiency. These factors include poorly controlled diabetes mellitus, alcohol ingestion, severe diarrhea and steatorrhea, and the use of a number of pharmacologic agents that induce renal Mg wasting. Manifestations of Mg deficiency include hypokalemia, hypocalcemia, neuromuscular hyperexcitability, respiratory muscle weakness, and intractable arrhythmias. Mg deficiency may also play a role in the genesis of myocardial ischemia. In this article, we review the assessment, causes, and manifestations of Mg deficiency and suggest guidelines for adequate treatment.

Dis Mon. 1988 Apr;34(4):161-218.

Magnesium metabolism in health and disease.

Elin RJ.

Clinical Pathology Department, National Institutes of Health, Bethesda, Maryland.

Magnesium is an important element for health and disease. Magnesium, the second most abundant intracellular cation, has been identified as a cofactor in over 300 enzymatic reactions involving energy metabolism and protein and nucleic acid synthesis. Approximately half of the total magnesium in the body is present in soft tissue, and the other half in bone. Less than 1% of the total body magnesium is present in blood. Nonetheless, the majority of our experimental information comes from determination of magnesium in serum and red blood cells. At present, we have little information about equilibrium among and state of magnesium within body pools. Magnesium is absorbed uniformly from the small intestine and the serum concentration controlled by excretion from the kidney. The clinical laboratory evaluation of magnesium status is primarily limited to the serum magnesium concentration, 24-hour urinary excretion, and percent retention following parenteral magnesium. However, results for these tests do not necessarily correlate with intracellular magnesium. Thus, there is no readily available test to determine intracellular/total body magnesium status. Magnesium deficiency may cause weakness, tremors, seizures, cardiac arrhythmias, hypokalemia, and hypocalcemia. The causes of hypomagnesemia are reduced intake (poor nutrition or IV fluids without magnesium), reduced absorption (chronic diarrhea, malabsorption, or bypass/resection of bowel), redistribution (exchange transfusion or acute pancreatitis), and increased excretion (medication, alcoholism, diabetes mellitus, renal tubular disorders, hypercalcemia, hyperthyroidism, aldosteronism, stress, or excessive lactation). A large segment of the U.S. population may have an inadequate intake of magnesium and may have a chronic latent magnesium deficiency that has been linked to atherosclerosis, myocardial infarction, hypertension, cancer, kidney stones, premenstrual syndrome, and psychiatric disorders. Hypermagnesemia is primarily seen in acute and chronic renal failure, and is treated effectively by dialysis.

Am Heart J. 1992 Aug;124(2):544-9.