justvitamin/data/evidence/calcium-citrate.json

{
  "handle": "calcium-citrate",
  "searchTerm": "\"calcium citrate\" AND (absorption OR bone OR supplementation)",
  "filtersApplied": "humans[Filter]+AND+(\"randomized+controlled+trial\"[Publication+Type]+OR+\"meta-analysis\"[Publication+Type])",
  "skus": [
    "JV-CALCIT"
  ],
  "generatedAt": "2026-06-02T08:24:30.555Z",
  "generatedBy": "scripts/ingest-pubmed-evidence.ts",
  "source": "PubMed E-utilities",
  "licence": "NCBI public domain (USA federal work)",
  "totalHits": 84,
  "studies": [
    {
      "pmid": "11329115",
      "title": "Meta-analysis of calcium bioavailability: a comparison of calcium citrate with calcium carbonate.",
      "journal": "American journal of therapeutics",
      "year": "1999",
      "firstAuthor": "Sakhaee K",
      "authorCount": 4,
      "publicationTypes": "Comparative Study, Journal Article, Meta-Analysis, Research Support, U.S. Gov't, P.H.S.",
      "doi": "",
      "url": "https://pubmed.ncbi.nlm.nih.gov/11329115/",
      "abstract": "OBJECTIVE: To perform a meta-analysis of data from available published trials comparing the bioavailability of calcium carbonate with that of calcium citrate. DATA SOURCES: The whole set was comprised of 15 studies involving 184 subjects who underwent measurement of calcium absorption from calcium carbonate and calcium citrate. Category A excluded four studies for lack of physiological relevance, use of a mixed preparation with low content of calcium carbonate, or wide variability in results. Category B was comprised of five studies (from Category A) involving 71 subjects who took calcium supplements on an empty stomach. Category C was comprised of six studies (from Category A) involving 65 subjects who took calcium preparations with meals. METHOD: The meta-analysis of calcium absorption data from calcium carbonate and calcium citrate, with calculation of effect size and 95% confidence intervals. RESULTS: Calcium absorption from calcium citrate was consistently significantly higher than that from calcium carbonate by 20.0% in the whole set, by 24.0% in Category A, by 27.2% on an empty stomach, and by 21.6% with meals. CONCLUSION: Calcium citrate is better absorbed than calcium carbonate by approximately 22% to 27%, either on an empty stomach or co-administered with meals."
    },
    {
      "pmid": "39475860",
      "title": "The Effect of Multi-Ingredient Protein versus Collagen Supplementation on Satellite Cell Properties in Males and Females.",
      "journal": "Medicine and science in sports and exercise",
      "year": "2024",
      "firstAuthor": "Wageh M",
      "authorCount": 8,
      "publicationTypes": "Journal Article, Randomized Controlled Trial",
      "doi": "10.1249/MSS.0000000000003505",
      "url": "https://pubmed.ncbi.nlm.nih.gov/39475860/",
      "abstract": "INTRODUCTION: Skeletal muscle satellite cells (SC) contribute to the adaptive process of resistance exercise training (RET) and may be influenced by nutritional supplementation. However, little research exists on the impact of multi-ingredient supplementation on the SC response to RET. PURPOSE: We tested the effect of a multi-ingredient supplement (MIS) including whey protein, creatine, leucine, calcium citrate, and vitamin D on SC content and activity as well as myonuclear accretion, SC and myonuclear domain compared with a collagen control (COL) throughout a 10-wk RET program. METHODS: Twenty-six participants underwent a 10-wk linear RET program while consuming either the MIS or COL supplement twice daily. Muscle biopsies were taken from the vastus lateralis at baseline and 48 h after a bout of damaging exercise, before and after RET. Muscle tissue was analyzed for SC and myonuclear content, domain, acute SC activation, and fiber cross-sectional area (fCSA). RESULTS: MIS resulted in a greater increase in type II fCSA following 10 wk of RET (effect size (ES) = 0.89) but not myonuclear accretion or SC content. Change in myonuclei per fiber was positively correlated with type I and II and total fiber hypertrophy in the COL group only, indicating a robust independent effect of MIS on fCSA. Myonuclear domain increased similarly in both groups, whereas SC domain remained unchanged following RET. SC activation was similar between groups for all fiber types in the untrained state but showed a trend toward greater increases with MIS after RET (ES = 0.70). CONCLUSIONS: SC responses to acute damaging exercise and long-term RET are predominantly similar in MIS and COL groups. However, MIS can induce greater increases in type II fCSA with RET and potentially SC activation followin"
    },
    {
      "pmid": "35623880",
      "title": "Urate-lowering effect of calcium supplementation: Analyses of a randomized controlled trial.",
      "journal": "Clinical nutrition ESPEN",
      "year": "2022",
      "firstAuthor": "Cândido FG",
      "authorCount": 6,
      "publicationTypes": "Journal Article, Randomized Controlled Trial, Research Support, U.S. Gov't, Non-P.H.S.",
      "doi": "10.1016/j.clnesp.2022.02.121",
      "url": "https://pubmed.ncbi.nlm.nih.gov/35623880/",
      "abstract": "OBJECTIVE: To investigate if the gout-protective effect of low-fat dairy products could be attributed to the urate-lowering effect of calcium. METHODS: This is a placebo-controlled trial in which thirty-five adult (aged 18-42 years) female low-calcium consumers (<800 mg/d) were randomized to one of three treatment groups: low calcium breakfast (control, approximately 70 mg of calcium/d) -C or high-calcium breakfast ( approximately 770 mg/d) from calcium citrate - CIT or from skim milk - SM, during 45 consecutive days. Breakfasts were matched for potential confounders and were provided as part of an energy-restricted normoprotein diet containing an additional 800 mg of calcium/d. Dual-energy X-ray absorptiometry measurements (body fat assessment) and fasting blood samples (urate, ionic calcium, PTH, and 1,25-(OH)2-D3) were taken at baseline and the end of the experiment. CLINICAL TRIAL REGISTRATION: http://www.ensaiosclinicos.gov.br/ (RBR-7Q2N33). RESULTS: Despite no significant changes in total body weight/fat, CIT and SM led to a significant reduction in serum urate and ionic calcium, but did not affect PTH and vitamin D concentrations compared to C. CIT and SM reduced baseline serum urate by approximately 14% and approximately 17%, respectively. There was a trend to a positive correlation between changes in serum urate and changes in ionic calcium on day 45 (r = 0.327, P = 0.055). CONCLUSIONS: Calcium supplementation (770 mg/d from dairy or calcium citrate) reduced serum urate concentrations, suggesting that the gout-protective effect of low-fat dairy consumption is at least partly due to a urate-lowering effect of calcium."
    },
    {
      "pmid": "18258639",
      "title": "Calcium supplementation and bone mineral accretion in adolescent girls: an 18-mo randomized controlled trial with 2-y follow-up.",
      "journal": "The American journal of clinical nutrition",
      "year": "2008",
      "firstAuthor": "Lambert HL",
      "authorCount": 5,
      "publicationTypes": "Journal Article, Randomized Controlled Trial, Research Support, Non-U.S. Gov't",
      "doi": "",
      "url": "https://pubmed.ncbi.nlm.nih.gov/18258639/",
      "abstract": "BACKGROUND: A recent meta-analysis raised doubt as to whether calcium supplementation in children benefits spine and hip bone mineral density (BMD). OBJECTIVE: We used state-of-the-art measures of bone (fan-beam dual-energy X-ray absorptiometry and 4 bone turnover markers) to determine whether girls with low habitual calcium intake benefited from supplementation with a soluble form of calcium (calcium citrate malate dissolved in a fruit drink). DESIGN: The trial was an 18-mo randomized trial of calcium supplementation (792 mg/d) with follow-up 2 y after supplement withdrawal. Subjects were 96 girls (mean age: 12 y) with low calcium intakes (mean: 636 mg/d). The main outcome measure was change in total-body, lumbar spine, and total hip bone mineral content (BMC) during supplementation and 2 y after supplement withdrawal. Changes in BMD and bone turnover markers were secondary outcome measures. RESULTS: The mean additional calcium intake in the supplemented group was 555 mg/d. Compared with the control group, the supplemented group showed significantly (P < 0.05) greater gains in BMC (except at the total hip site) over the 18-mo study. BMD change was significantly (P < 0.05) greater for all skeletal sites, and concentrations of bone resorption markers and parathyroid hormone were significantly (P < 0.01) lower in the supplemented group than in the control group after 18 mo. After 42 mo, gains in BMC and BMD and differences in bone resorption were no longer evident. CONCLUSIONS: Calcium supplementation enhances bone mineral accrual in teenage girls, but the effect is short-lived. The likely mechanism for the effect of the calcium is suppression of bone turnover, which is reversed upon supplement withdrawal."
    },
    {
      "pmid": "8340983",
      "title": "Calcium supplementation and bone mineral density in adolescent girls.",
      "journal": "JAMA",
      "year": "1993",
      "firstAuthor": "Lloyd T",
      "authorCount": 9,
      "publicationTypes": "Clinical Trial, Journal Article, Randomized Controlled Trial, Research Support, Non-U.S. Gov't, Research Support, U.S. Gov't, P.H.S.",
      "doi": "",
      "url": "https://pubmed.ncbi.nlm.nih.gov/8340983/",
      "abstract": "OBJECTIVE: To evaluate the effect of calcium supplementation on bone acquisition in adolescent white girls. DESIGN: A randomized, double-blind, placebo-controlled trial of the effect of 18 months of calcium supplementation on bone density and bone mass. SUBJECTS: Ninety-four girls with a mean age of 11.9 + 0.5 years at study entry. SETTING: University hospital in a small town. INTERVENTIONS: Calcium supplementation, 500 mg/d calcium as calcium citrate malate; controls received placebo pills. MAIN OUTCOME MEASURES: Bone mineral density and bone mineral content of the lumbar spine and total body were measured by dual-energy x-ray absorptiometry and calcium excretion from 24-hour urine specimens. RESULTS: Calcium intake from dietary sources averaged 960 mg/d for the entire study group. The supplemented group received, on average, an additional 354 mg/d of calcium. The supplemented group compared with the placebo group had greater increases of lumbar spine bone density (18.7% vs 15.8%; P = .03), lumbar spine bone mineral content (39.4% vs 34.7%; P = .06), total body bone mineral density (9.6% vs 8.3%; P = .05), and 24-hour urinary calcium excretion (90.4 vs 72.9 mg/d; P = .02), respectively. CONCLUSIONS: Increasing daily calcium intake from 80% of the recommended daily allowance to 110% via supplementation with calcium citrate malate resulted in significant increases in total body and spinal bone density in adolescent girls. The increase of 24 g of bone gain per year among the supplemented group translates to an additional 1.3% skeletal mass per year during adolescent growth, which may provide protection against future osteoporotic fracture."
    },
    {
      "pmid": "16945613",
      "title": "Randomized controlled trial of calcium in healthy older women.",
      "journal": "The American journal of medicine",
      "year": "2006",
      "firstAuthor": "Reid IR",
      "authorCount": 8,
      "publicationTypes": "Journal Article, Randomized Controlled Trial",
      "doi": "",
      "url": "https://pubmed.ncbi.nlm.nih.gov/16945613/",
      "abstract": "PURPOSE: Calcium has been shown to have positive effects on bone mineral density in postmenopausal women. However, these effects are small, it is unknown whether they are sustained with long-term use, they have not been shown with intention-to-treat analyses, and the evidence for fracture prevention with calcium monotherapy is inconsistent. METHODS: A randomized controlled trial of calcium (1 g/day as the citrate) in 1471 healthy postmenopausal women (aged 74+/-4 years) was performed to assess the effects on bone density and fracture incidence over 5 years. RESULTS: Follow-up was complete in 90% of subjects, and average medication compliance was 55% to 58%. Calcium had a significant beneficial effect on bone density (intention-to-treat analysis), with between-groups differences at 5 years of 1.8% (spine), 1.6% (total hip), and 1.2% (total body). Effects were greater in a per-protocol analysis (5-year differences of 2.3%, 2.8%, and 1.8%, respectively). A total of 425 fractures occurred in 281 women. Hazard ratios, based on time to first fracture, were 0.90 (95% confidence interval [CI], 0.71-1.16) for any symptomatic fracture, 0.72 (95% CI, 0.44-1.18) for vertebral, 3.55 (95% CI, 1.31-9.63) for hip, and 0.65 (95% CI, 0.41-1.04) for forearm fracture. Per-protocol analysis found respective hazard ratios of 0.86 (95% CI, 0.64-1.17), 0.62 (95% CI, 0.33-1.16), 3.24 (95% CI, 0.65-16.1), and 0.45 (95% CI, 0.24-0.87). Height loss was reduced by calcium in the per-protocol population (P=.03). Serum alkaline phosphatase and procollagen type-I N-terminal propeptide were lower in the calcium group at 5 years, but constipation was more common. CONCLUSIONS: Calcium results in a sustained reduction in bone loss and turnover, but its effect on fracture remains uncertain. Poor long-term "
    },
    {
      "pmid": "10367025",
      "title": "Absorption of calcium as the carbonate and citrate salts, with some observations on method.",
      "journal": "Osteoporosis international : a journal established as result of cooperation between the European Foundation for Osteoporosis and the National Osteoporosis Foundation of the USA",
      "year": "1999",
      "firstAuthor": "Heaney RP",
      "authorCount": 3,
      "publicationTypes": "Clinical Trial, Comparative Study, Journal Article, Randomized Controlled Trial, Research Support, U.S. Gov't, P.H.S.",
      "doi": "",
      "url": "https://pubmed.ncbi.nlm.nih.gov/10367025/",
      "abstract": "Calcium supplement use has increased and there is confusion about the relative absorbability of various sources. Absorbability of calcium from the carbonate and citrate salts was compared at 300 mg and 1000 mg calcium loads, ingested as part of a light breakfast meal. Absorption was measured at the high load both by tracer appearance in serum and by the absorptive increment in urinary calcium, and at the low load by the tracer method only. Subjects were 37 healthy adult men and women, studied as outpatients, and each tested on both salts at the same load. Mean tracer absorption (+/- SD) for both salts combined was 36.0% at the 300 mg load and 28.4% at the 1000 mg load. In both experiments the observed mean difference in absorption between salts was very small. By the tracer method the within-subject difference (carbonate less citrate) was +3.3% +/- 1.2% of the ingested dose (mean +/- SEM; P < 0.05) at the high load, and at the low load, 3.6% +/- 2.7% (NS). Combining the two experiments yielded zero difference between sources. By the urinary calcium increment method, the mean difference between salts at the 1000 mg load was 1.8 +/- 4.1 mg (NS). Side-by-side comparisons of the two methods revealed that the tracer method was 3 times more sensitive than the urinary increment method. We conclude that, when taken with food, calcium from the carbonate salt is fully as absorbable as from the citrate, and that the urinary increment method is not sufficiently sensitive to be useful in comparing sources in free-living subjects."
    },
    {
      "pmid": "3614304",
      "title": "Gastrointestinal absorption of calcium from milk and calcium salts.",
      "journal": "The New England journal of medicine",
      "year": "1987",
      "firstAuthor": "Sheikh MS",
      "authorCount": 5,
      "publicationTypes": "Clinical Trial, Comparative Study, Journal Article, Randomized Controlled Trial, Research Support, Non-U.S. Gov't, Research Support, U.S. Gov't, P.H.S.",
      "doi": "",
      "url": "https://pubmed.ncbi.nlm.nih.gov/3614304/",
      "abstract": "Whether ingested calcium is absorbed more efficiently from freely water-soluble calcium salts than from poorly soluble salts is unclear. It is also unknown whether calcium is absorbed better from dairy products than from calcium salts. Using a method by which the net absorption of calcium can be accurately measured after a single dose, we studied eight healthy fasting subjects after they took a 500-mg dose of calcium from each of five calcium salts with various degrees of water solubility and from milk. The order of administration of the agents given was randomly determined. The mean (+/- SEM) net calcium absorption, in decreasing order of the solubility of the salts, was 32 +/- 4 percent from calcium acetate, 32 +/- 4 percent from calcium lactate, 27 +/- 3 percent from calcium gluconate, 30 +/- 3 percent from calcium citrate, and 39 +/- 3 percent from calcium carbonate. The differences in absorption were not statistically significant according to analysis of variance. On the basis of in vitro solubility experiments in acid mediums, we hypothesize that acid dissolution in the gastrointestinal tract may be responsible for the similar absorption of calcium from salts with widely different water solubilities. Calcium absorption from whole milk (31 +/- 3 percent) was similar to absorption from calcium salts. We conclude that calcium absorption from carbonate, acetate, lactate, gluconate, and citrate salts of calcium, and from whole milk, is similar in fasting healthy young subjects. Further study will be required to determine whether the results would be different in older subjects, with a higher dose of calcium, or if the calcium was ingested with food."
    }
  ]
}