SynthesisNutrition journal2009
Phosphate decreases urine calcium and increases calcium balance: a meta-analysis of the osteoporosis acid-ash diet hypothesis.
Synthesis in Nutrition journal, 2009. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 33 papers, 4 of them syntheses that pooled it.
What it found
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The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
33 citing papers in PubMed, 4 syntheses or guidelines pooled it, 74 citations in OpenAlex.
- Systematic review and meta-analysis of the association between dairy consumption and the risk of hip fracture: critical interpretation of the currently available evidence.Osteoporosis international : a journal established as result of cooperation between the European Foundation for Osteoporosis and the National Osteoporosis Foundation of the USA · 2020Pooled it
- Systematic review of the association between dietary acid load, alkaline water and cancer.BMJ open · 2016Pooled it
- Non-pharmacological management of osteoporosis: a consensus of the Belgian Bone Club.Osteoporosis international : a journal established as result of cooperation between the European Foundation for Osteoporosis and the National Osteoporosis Foundation of the USA · 2011Pooled it
- Causal assessment of dietary acid load and bone disease: a systematic review & meta-analysis applying Hill's epidemiologic criteria for causality.Nutrition journal · 2011Pooled it
- Whey Protein Supplementation and Higher Total Protein Intake Do Not Influence Bone Quantity in Overweight and Obese Adults Following a 36-Week Exercise and Diet Intervention.The Journal of nutrition · 2017Trial
- Hypercalciuria associated with high dietary protein intake is not due to acid load.The Journal of clinical endocrinology and metabolism · 2011Trial
- Dietary mineral insufficiency and osteoporosis risk across skeletal sites in older Iranian adults: IMOS-2021.Journal of bone and mineral metabolism · 2026Article
- Effect of a Milk Protein Concentrate Supplement on Muscle Recovery and Oxidative Stress Following Knee and Hip Arthroplasty: A Randomized Control Trial.Antioxidants (Basel, Switzerland) · 2026Article
- Composite Phenotype: Recurrent Nephrolithiasis and Chronic Kidney Disease in an Adult with Biallelic <italic>SLC34A3</italic> and Monoallelic <italic>SLC3A1</italic> Pathogenic Variants - Who Is "The Culprit"?Kidney & blood pressure research · 2026Article
- Causal inference in health and disease: a review of the principles and applications of Mendelian randomization.Journal of bone and mineral research : the official journal of the American Society for Bone and Mineral Research · 2024Review
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- Editorial: New insights and advances in body recomposition.Frontiers in nutrition · 2024Article
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- The Effects of Calcium, Magnesium, Phosphorus, Fluoride, and Lead on Bone Tissue.Biomolecules · 2021Review
- Benefits and safety of dietary protein for bone health-an expert consensus paper endorsed by the European Society for Clinical and Economical Aspects of Osteopororosis, Osteoarthritis, and Musculoskeletal Diseases and by the International Osteoporosis Foundation.Osteoporosis international : a journal established as result of cooperation between the European Foundation for Osteoporosis and the National Osteoporosis Foundation of the USA · 2018Review
- High Dietary Protein Intake and Protein-Related Acid Load on Bone Health.Current osteoporosis reports · 2017Review
- Nutrition and osteoporosis prevention for the orthopaedic surgeon: A wholefoods approach.EFORT open reviews · 2017Article
- Evidence does not support the alkaline diet.Osteoporosis international : a journal established as result of cooperation between the European Foundation for Osteoporosis and the National Osteoporosis Foundation of the USA · 2016Article
Corrections and comments
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Authors and funding
5 authors at 3 institutions in 1 country.
Funding
No grant is acknowledged in the PubMed record.
Abstract
backgroundThe acid-ash hypothesis posits that increased excretion of "acidic" ions derived from the diet, such as phosphate, contributes to net acidic ion excretion, urine calcium excretion, demineralization of bone, and osteoporosis. The public is advised by various media to follow an alkaline diet to lower their acidic ion intakes. The objectives of this meta-analysis were to quantify the contribution of phosphate to bone loss in healthy adult subjects; specifically, a) to assess the effect of supplemental dietary phosphate on urine calcium, calcium balance, and markers of bone metabolism; and to assess whether these affects are altered by the b) level of calcium intake, c) the degree of protonation of the phosphate.
methodsLiterature was identified through computerized searches regarding phosphate with surrogate and/or direct markers of bone health, and was assessed for methodological quality. Multiple linear regression analyses, weighted for sample size, were used to combine the study results. Tests of interaction included stratification by calcium intake and degree of protonation of the phosphate supplement.
resultsTwelve studies including 30 intervention arms manipulated 269 subjects' phosphate intakes. Three studies reported net acid excretion. All of the meta-analyses demonstrated significant decreases in urine calcium excretion in response to phosphate supplements whether the calcium intake was high or low, regardless of the degree of protonation of the phosphate supplement. None of the meta-analyses revealed lower calcium balance in response to increased phosphate intakes, whether the calcium intake was high or low, or the composition of the phosphate supplement.
conclusionAll of the findings from this meta-analysis were contrary to the acid ash hypothesis. Higher phosphate intakes were associated with decreased urine calcium and increased calcium retention. This meta-analysis did not find evidence that phosphate intake contributes to demineralization of bone or to bone calcium excretion in the urine. Dietary advice that dairy products, meats, and grains are detrimental to bone health due to "acidic" phosphate content needs reassessment. There is no evidence that higher phosphate intakes are detrimental to bone health.
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Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.