Calcium: benefits, dosage, contraindications
Other name(s)
Ca
Family or group:
Minerals and trace elements
Indications
Rating methodology
EFSA approval.
Digestive disorders ✪✪✪✪✪
A dose of 750 mg four times a day of an antacid containing only calcium carbonate seems to be largely sufficient.
Posologie
Oral
750 - 3000 mg
Adults
calcium carbonate
Hypocalcemia ✪✪✪✪✪
In cases of mild hypocalcemia, it is sufficient to consume more calcium-rich foods. However, when calcium levels drop below 1.9 mmol/L, in cases of acute symptomatic hypocalcemia, urgent hospitalization is strongly recommended for slow intravenous calcium administration. The recommended daily intake for individuals aged 25 and above is estimated at 950 mg/day and 1000 mg/day for young adults (18-24 years) who are still accumulating calcium in their bones. Moreover, for children aged 1 to 3 years, 4 to 10 years, and 11 to 17 years, the recommended intakes are 450, 800, and 1150 mg/day, respectively.
Posologie
Oral
450 - 1150 mg
Children, Adults, Seniors, Infants
calcium carbonate
Kidney failure ✪✪✪✪✪
Taking calcium carbonate or calcium acetate orally is effective as a phosphate binder, preventing its absorption, thereby reducing hyperphosphatemia associated with kidney failure. Calcium citrate is not recommended for this purpose as it increases aluminum absorption and does not bind phosphate as effectively as calcium acetate or calcium carbonate. Calcium acetate or calcium carbonate, 1 to 6.5 g/day in divided doses, generally for 2 to 52 weeks, have been used.
Posologie
Oral
1 - 6.5 g
Adults
calcium carbonate
Benefits and harms of phosphate binders in CKD: a systematic review of randomized controlled trials.
Renal phosphate handling and calcium nephrolithiasis: role of dietary phosphate and phosphate leak.
A comparison of clinically useful phosphorus binders for patients with chronic kidney failure.
Bone health ✪✪✪✪✪
Peak bone growth occurs during adolescence, then bone density in women remains relatively constant until the age of 30 to 40 years. After 40, bone loss usually occurs at rates of 0.5% to 1% per year. In men, this happens several decades later. The loss is more pronounced if dietary calcium intake is below the recommended daily intake. Calcium supplements are widely prescribed to promote bone health, including for the treatment and prevention of osteoporosis, a major cause of morbidity and mortality in the elderly. Several studies have shown that calcium could be considered a low-potency anti-resorptive agent that must be taken in conjunction with a sufficient amount of vitamin D.
Posologie
Oral
1000 - 2500 mg
Adults
calcium carbonate
Synergies
Child development ✪✪✪✪✪
The European health authorities (EFSA, European Food Safety Authority and the European Commission) have determined that products containing calcium can claim to contribute to the maintenance of bones and teeth and support bone growth and development in children, only if these products contain at least 120 mg of calcium per 100 g, 100 ml, or per package if the product contains only one serving. Calcium supplementation in pregnant women with low dietary calcium intake (less than 562 mg of elemental calcium per day) increases fetal bone mineralization and density. However, for women with adequate dietary intake, calcium supplementation offers no additional benefit.
Posologie
Orally
450 - 1150 mg
Children
calcium carbonate
Osteoporosis ✪✪✪✪✪
The optimal calcium dose to reduce the risk of bone fractures is debated. A population study found that consuming 750 mg/day of elemental calcium reduced fracture risk, while higher doses offered no additional benefit. Additionally, recommendations published by the U.S. Preventive Services Task Force suggest that taking daily doses of 1000 mg or less of calcium, combined with 400 mg or less of vitamin D, is inadequate for the primary prevention of fractures in postmenopausal women. Most experts recommend taking 1000 to 1200 mg per day for the prevention of osteoporosis and/or fractures. It's preferable to split the dose in two since calcium is better absorbed when taken in doses of 500 mg or less (elemental calcium). Attention should also be paid to the amount of elemental calcium present in each tablet. Indeed, a 1250 mg calcium carbonate tablet, for example, may contain only 500 mg of elemental calcium. Calcium citrate and calcium carbonate are the two most common forms of calcium supplements. The European health authorities (EFSA, European Food Safety Authority and the European Commission) believe that foods and supplements providing at least 400 mg of calcium per serving (and ideally at least 15 micrograms of vitamin D) can claim to help reduce bone mineral density loss in postmenopausal women aged 50 and over.
Posologie
Orally
1000 - 1200 mg
Seniors
calcium carbonate, calcium citrate
Synergies
Clinician's Guide to Prevention and Treatment of Osteoporosis.
Dietary calcium intake and risk of fracture and osteoporosis: prospective longitudinal cohort study.
Postmenopausal osteoporosis. Strategies for preventing bone loss, avoiding fracture.
Pregnancy ✪✪✪✪✪
Clinical research shows that daily intake of 1 to 2 g of calcium orally reduces pregnancy-related hypertension and preeclampsia. Calcium appears to reduce the risk of preeclampsia by about 50% compared to a placebo. An analysis of 19 controlled trials involving over 29,000 pregnant women revealed that for every 19 women treated with calcium, one episode of preeclampsia would be avoided. The World Health Organization (WHO) recommends prescribing oral calcium supplementation of 1.5 to 2 g per day starting in the second trimester to high-risk women with low dietary calcium intake to prevent preeclampsia.
Posologie
Orally
1 - 2 g
Pregnant women
calcium carbonate
Supplementary calcium in prevention of pre-eclampsia.
WHO recommendations on antenatal care for a positive pregnancy experience
Nutritional interventions for the prevention of maternal morbidity.
Effect of calcium supplementation on pregnancy-induced hypertension and preeclampsia: a meta-analysis of randomized controlled trials.
Calcium supplementation and prevention of pregnancy induced hypertension.
Calcium supplementation in nulliparous women for the prevention of pregnancy-induced hypertension, preeclampsia and preterm birth: an Australian randomized trial. FRACOG and the ACT Study Group.
Premenstrual Syndrome ✪✪✪✪✪
In women, calcium levels may be lower during the premenstrual period due to the effects of fluctuating estrogen levels on calcium absorption and metabolism. This may contribute to mood changes and other symptoms associated with premenstrual syndrome (PMS). Calcium has been used at a dose of 1000 to 1336 mg/day for three menstrual cycles. A specific supplement containing 400 mg of calcium and 400 IU of vitamin D taken daily for 3 months has also been used.
Posologie
Orally
1000 - 1336 mg
Adults
calcium carbonate
Synergies
Colorectal Cancer ✪✪✪✪✪
Clinical and demographic studies have shown that increased dietary calcium intake or use of dietary supplements reduces the risk of colorectal cancer and colonic adenoma. A meta-analysis of 10 cohort studies showed a reduced risk of colorectal cancer in individuals with higher calcium intake. Other clinical trials show that taking calcium supplements ranging from 1.2 to 2 grams per day for 4 years can reduce the risk of recurrent colorectal adenoma by up to 29%. A meta-analysis suggests that daily intake of 1200 mg of calcium reduces the risk of colorectal adenomas in individuals with a normal BMI (body mass index), but not in those who are overweight or obese. However, clinical research results concerning the protective effect of calcium against colorectal cancer and adenoma remain contradictory. Vitamin D could be an important factor explaining this contradiction. Individuals with below-average vitamin D levels do not seem to benefit from calcium supplements.
Posologie
Orally
1200 - 2000 mg
Adults
calcium carbonate
Colorectal cancer risk and dietary intake of calcium, vitamin D, and dairy products: a meta-analysis of 26,335 cases from 60 observational studies
Effects of calcium on the incidence of recurrent colorectal adenomas: A systematic review with meta-analysis and trial sequential analysis of randomized controlled trials
Role of supplemental calcium in the recurrence of colorectal adenomas: a metaanalysis of randomized controlled trials
Dietary calcium and vitamin D intake and risk of colorectal cancer: a prospective cohort study in women
Calcium intake and colorectal cancer risk: dose-response meta-analysis of prospective observational studies
Dietary calcium supplementation for preventing colorectal cancer and adenomatous polyps
Calcium supplements for the prevention of colorectal adenomas. Calcium Polyp Prevention Study Group
Dairy foods, calcium, and colorectal cancer: a pooled analysis of 10 cohort studies
Calcium intake and colorectal adenoma risk: dose-response meta-analysis of prospective observational studies
Supplemental calcium in the chemoprevention of colorectal cancer: a systematic review and meta-analysis
Chemoprevention of colorectal cancer: systematic review and economic evaluation
Vitamin D, calcium supplementation, and colorectal adenomas: results of a randomized trial
Hypertension ✪✪✪✪✪
Research conducted among women over 45 suggests that higher calcium intake from both diet and supplements is associated with a lower risk of developing hypertension compared to women with lower calcium intake. Other research, conducted among patients with or without hypertension, shows that increased dietary calcium intake or calcium supplements can slightly lower blood pressure. This effect is more significant in individuals whose basal dietary calcium intake is low.
Posologie
Orally
1000 - 2000 mg
Adults
calcium carbonate
Dietary calcium and blood pressure: a meta-analysis of randomized clinical trials
Effects of dietary calcium supplementation on blood pressure. A meta-analysis of randomized controlled trials
Calcium supplementation for the management of primary hypertension in adults
Calcium from dairy products, vitamin D intake, and blood pressure: the Tromso Study
Blood pressure response to calcium supplementation: a meta-analysis of randomized controlled trials
Effects of calcium supplementation on body weight and blood pressure in normal older women: a randomized controlled trial
The influence of dietary and nondietary calcium supplementation on blood pressure: an updated metaanalysis of randomized controlled trials
Calcium supplementation in patients with essential hypertension: assessment by office, home and ambulatory blood pressure
Properties
Essential
Bones and teeth contain more than 99% of the calcium in the human body. Calcium is also found in the blood, extracellular fluid, muscles, and other tissues. It is essential for nerve transmission, muscle contraction, vascular contraction, vasodilatation, glandular secretion, membrane and capillary permeability, enzymatic reactions, respiration, kidney function, and blood clotting. It also plays a role in the release and storage of hormones and neurotransmitters, the absorption and fixation of amino acids, the absorption of cyanocobalamin (vitamin B12), and the secretion of gastrin (a hormone secreted by G cells in the pyloric mucosa of the stomach). Calcium in bones is a reserve source that can be mobilized to maintain extracellular calcium concentrations.
Usages associés
Digestive Effect
Calcium carbonate is an inorganic salt used as an antacid. It is a basic compound that acts by neutralizing hydrochloric acid in gastric secretions. Its alkalizing effect can inhibit pepsin action. Additionally, calcium is sometimes used in renal failure patients because it can bind to phosphate in the intestine, preventing its absorption and reducing hyperphosphatemia associated with kidney failure.
Usages associés
Cardiovascular
Evidence suggests that insufficient dietary calcium intake may induce the development of hypertension, strokes, and cardiovascular diseases. Calcium could lower blood pressure by increasing sodium excretion via the kidneys. Animal studies suggest it may also prevent salt-induced hypertension (sodium chloride). Moreover, calcium is a highly effective membrane stabilizer in treating rhythm disorders associated with hyperkalemia (high potassium levels). However, it has no preventive efficacy and should, therefore, be administered only when arrhythmia is observed. More recently, some population studies suggest that higher calcium intake alone or combined with vitamin D is associated with a lower risk of developing type 2 diabetes. The mechanism of action is not fully elucidated. A meta-analysis of clinical research shows that calcium supplementation of 1000 mg or more per day, combined with vitamin D supplementation of 2000 IU or more per day, can reduce fasting blood glucose and insulin resistance in non-diabetic patients.
Usages associés
Bone Density
The role of calcium as a treatment remains unclear due to a lack of data in non-deficient individuals. However, this mineral seems likely to suppress biochemical markers of bone resorption only in active and non-sedentary subjects.
Usages associés
Anticancer
A relationship between dairy product consumption and cancer incidence has been established, with evidence of protective effects of calcium depending on both the type of cancer and the timing of exposure. Studies suggest that calcium may have an antiproliferative effect on colorectal cancer cells. Calcium intake alone does not seem to significantly reduce cancer risk. However, the role of calcium in cancer prevention when taken with vitamin D is controversial, as the results remain contradictory.
Usages associés
Safety dosage
Adults aged 25 and over: 950 mg - 2500 mg
Lactating women aged 25 and over: 950 mg - 2500 mg
Pregnant women aged 25 and over: 950 mg - 2500 mg
Adults aged 18 to 24: 1000 mg - 2500 mg
Lactating women aged 18 to 24: 1000 mg - 2500 mg
Children aged 1 to 3: 450 mg
Children aged 4 to 10: 800 mg
Children aged 11 to 17: 1150 mg
Pregnant women aged 18 to 24: 1000 mg - 2500 mg
Interactions
Médicaments
Integrase inhibitors: strong interaction
Calcium seems to decrease the levels of integrase inhibitors (dolutegravir, elvitegravir, raltegravir), used in HIV infections, through a chelation mechanism.
Bisphosphonates: moderate interaction
Calcium supplements reduce the absorption of bisphosphonates.
Aluminum: moderate interaction
Calcium citrate can increase aluminum absorption when taken with aluminum hydroxide. Elevated aluminum levels can become toxic, especially in individuals with kidney disease. However, the effect of calcium citrate on aluminum absorption is due to the citrate anion rather than the calcium cation. Calcium acetate does not appear to increase aluminum absorption.
Levothyroxine: moderate interaction
Calcium reduces the absorption of levothyroxine, likely due to the formation of insoluble complexes. Calcium carbonate supplements reduce the efficacy of levothyroxine in patients with hypothyroidism.
Lithium: moderate interaction
Clinical evidence suggests that long-term use of lithium can cause hypercalcemia in 10% to 60% of patients. Theoretically, the concomitant use of lithium and calcium may increase the risk of hypercalcemia.
Quinolones: moderate interaction
Orally, calcium can bind to quinolones in the intestine and reduce their absorption.
Sotalol: moderate interaction
Calcium appears to reduce the absorption of sotalol (an anti-arrhythmic treatment), likely by forming insoluble complexes.
Calcipotriol: moderate interaction
Calcipotriol, a structural analogue of vitamin D used topically for psoriasis, can be absorbed in sufficient quantities to cause systemic effects, including hypercalcemia. Theoretically, combining calcipotriol with calcium supplements may increase the risk of hypercalcemia.
Anticonvulsants: strong interaction
Phenytoin (Dilantin), fosphenytoin (Cerebyx), phenobarbital, and carbamazepine (Tegretol) decrease calcium absorption by increasing the metabolism of vitamin D, which is necessary for calcium absorption. Supplementation with calcium and vitamin D may be necessary, especially if the treatment is prolonged.
Precautions
Hypothyroidism: use with caution
Calcium carbonate reduces the absorption of levothyroxine and decreases its efficacy in hypothyroid patients under treatment.
Hypophosphatemia: use with caution
Calcium supplements should be used with caution in patients with low serum phosphate levels. If calcium intake increases without a simultaneous increase in phosphorus intake, phosphorus absorption may decrease, thereby worsening phosphorus deficiency.
