{"ok":true,"entry":{"slug":"calcium","kind":"supplement","name":"calcium","aliases":["calcium carbonate","calcium citrate","Caltrate"],"brands_sg":["California Gold Nutrition","21st Century","Life Extension","Nature's Bounty","NOW Foods"],"class":"mineral","tags":["bone-joint"],"use_for":"bones and teeth · normal muscle and nerve function","use_after":"with food · ≤500 mg at a time · 4 h from levothyroxine","use_duration":null,"take_with":"vitamin d (required for uptake) · citrate works without food","pros":["rda 1,000 mg a day (19–50); food counts","hsa allows bone, teeth, muscle and nerve claims","with vitamin d, raised bone density in older adults"],"cons":["fracture prevention: trial results are mixed","carbonate causes more gas and constipation than citrate","supplements linked to kidney stones · heart data mixed"],"dose_note":"rda is 1,000 mg a day for adults 19–50 and men to 70, 1,200 mg for women 51+ and everyone over 70, from all sources; ul is 2,500 mg a day at 19–50 and 2,000 mg from 51; absorption from supplements is highest at 500 mg or less per dose; hsa's general-adult limit for health supplements in singapore is 1,200 mg a day","dosage":{"ul":"2,500 mg (19–50) · 2,000 mg (51+)","unit":"mg","fda_dv":"1,300 mg","rda_ai":"1,000 mg (19–50; men to 70) · 1,200 mg (women 51+, all 71+)","ul_status":"established","population":"general adult","hsa_max_daily":"1,200 mg"},"ul_status":"established","sg_class":null,"cautions":["history of kidney stones — the ul rests on a stone-risk link seen with supplemental calcium; ask your doctor first","heart concerns — supplement studies point both ways; an expert panel called intakes below the ul safe 'from a cardiovascular standpoint'","on lithium long term — blood calcium can run high; supplements may add to that; ask your doctor","low stomach acid or older age — carbonate absorbs poorly away from meals; citrate is less acid-dependent"],"clashes":[{"src":["nih_ods_calcium_interactions"],"note":"carbonate cuts its absorption; fda label: not within 4 h of the supplement","with":"levothyroxine"},{"src":["nih_ods_calcium_interactions"],"note":"less antibiotic absorbed; antibiotic 2 h before or 2 h after calcium","with":"quinolone antibiotics (ciprofloxacin, moxifloxacin, gemifloxacin)"},{"src":["nih_ods_calcium_interactions"],"note":"drug levels fall substantially; label: 2 h before or 6 h after calcium","with":"dolutegravir"},{"src":["nih_ods_calcium_interactions"],"note":"long-term lithium can cause hypercalcemia; calcium supplements may raise that risk","with":"lithium"},{"src":["nih_ods_iron_con"],"note":"may interfere with iron absorption; the two at different times of day may prevent this","with":"iron supplements"}],"sources":[{"id":"nih_ods_calcium_intake","url":"https://ods.od.nih.gov/factsheets/Calcium-HealthProfessional/","label":"NIH ODS — Calcium Fact Sheet for Health Professionals (updated June 22, 2026; read via archive.org capture, see verify_notes) — Table 1 RDAs; Introduction","quote":"19–50 years 1,000 mg … 51–70 years 1,000 mg 1,200 mg … >70 years 1,200 mg … Calcium makes up much of the structure of bones and teeth … Vitamin D is required for calcium to be absorbed in the gut by active transport","accessed":"2026-08-27"},{"id":"nih_ods_calcium_forms","url":"https://ods.od.nih.gov/factsheets/Calcium-HealthProfessional/","label":"NIH ODS — Calcium Fact Sheet for Health Professionals (updated June 22, 2026; read via archive.org capture, see verify_notes) — Sources of Calcium — Dietary supplements (absorption)","quote":"absorption of calcium supplements is greater when they are taken with food … Calcium citrate is less dependent on stomach acid for absorption than calcium carbonate … Absorption from supplements is highest with doses of 500 mg or less","accessed":"2026-08-27"},{"id":"nih_ods_calcium_gi","url":"https://ods.od.nih.gov/factsheets/Calcium-HealthProfessional/","label":"NIH ODS — Calcium Fact Sheet for Health Professionals (updated June 22, 2026; read via archive.org capture, see verify_notes) — Sources of Calcium — Dietary supplements (side effects)","quote":"gastrointestinal side effects, including gas, bloating, constipation … Calcium carbonate appears to cause more of these side effects than calcium citrate, especially in older adults who have lower levels of stomach acid","accessed":"2026-08-27"},{"id":"nih_ods_calcium_evidence","url":"https://ods.od.nih.gov/factsheets/Calcium-HealthProfessional/","label":"NIH ODS — Calcium Fact Sheet for Health Professionals (updated June 22, 2026; read via archive.org capture, see verify_notes) — Calcium and Health — Bone health in older adults","quote":"supplementation with calcium alone or a combination of calcium and vitamin D increases BMD in older adults … whether these BMD increases were clinically significant is not clear … research on the use of calcium supplementation to prevent fractures … are mixed","accessed":"2026-08-27"},{"id":"nih_ods_calcium_ul","url":"https://ods.od.nih.gov/factsheets/Calcium-HealthProfessional/","label":"NIH ODS — Calcium Fact Sheet for Health Professionals (updated June 22, 2026; read via archive.org capture, see verify_notes) — Health Risks from Excessive Calcium; Table 3 ULs","quote":"19–50 years 2,500 mg … 51–70 years 2,000 mg … >70 years 2,000 mg … The ULs for calcium … are based on observational evidence from the WHI showing a link between higher intakes of supplemental calcium … and a greater risk of kidney stones","accessed":"2026-08-27"},{"id":"nih_ods_calcium_cvd","url":"https://ods.od.nih.gov/factsheets/Calcium-HealthProfessional/","label":"NIH ODS — Calcium Fact Sheet for Health Professionals (updated June 22, 2026; read via archive.org capture, see verify_notes) — Calcium and Health — Cardiovascular disease","quote":"the use of calcium supplements might actually increase the risk of cardiovascular disease, while other studies have found no link … calcium intakes that do not exceed the UL are safe \"from a cardiovascular standpoint.\"","accessed":"2026-08-27"},{"id":"nih_ods_calcium_interactions","url":"https://ods.od.nih.gov/factsheets/Calcium-HealthProfessional/","label":"NIH ODS — Calcium Fact Sheet for Health Professionals (updated June 22, 2026; read via archive.org capture, see verify_notes) — Interactions with Medications","quote":"dolutegravir 2 hours before or 6 hours after taking calcium supplements … avoid taking levothyroxine within 4 hours … Long-term use of lithium … can lead to hypercalcemia … quinolone antibiotics … can reduce the absorption of quinolones … 2 hours before or 2 hours after","accessed":"2026-08-27"},{"id":"fda_dv","url":"https://www.fda.gov/food/nutrition-facts-label/daily-value-nutrition-and-supplement-facts-labels","label":"FDA — Daily Value on the Nutrition and Supplement Facts Labels, Reference Guide: Daily Values for Nutrients (content current as of 03/05/2024)","quote":"DVs are the recommended amounts of nutrients to consume or not to exceed each day … Calcium … 1300mg","accessed":"2026-08-27"},{"id":"hsa_hs_guidelines","url":"https://file.go.gov.sg/hsa-hs-guidelines.pdf","label":"HSA Singapore — Health Supplements Guidelines GL-CHPB-3-001 Rev. No. 020, January 2026 — clause 4.8, Table 5 Minerals Limits + List of Health Claims","quote":"HS for use by the general adult population should not contain vitamins and minerals exceeding the stipulated limits … Calcium 1200 mg … normal teeth • Calcium … normal muscle function • Calcium … normal neurotransmission • Calcium … Maintain/support bone health • Boron, calcium, magnesium, manganese, phosphorus, zinc","accessed":"2026-08-27"},{"id":"hsa_prohibited","url":"https://file.go.gov.sg/hsa-chp-prohibited-restricted-ing-guidelines.pdf","label":"HSA Singapore — Guidelines on Prohibited and Restricted Ingredients in Health Supplements and Traditional Medicines GL-CHPB-1-012 Rev. No. 001, October 2025 — Annex A row 17","quote":"17. Calcium Restricted use in HS and TM … When for oral use by general adult population, the maximum recommended daily dose should not provide more than 1200mg","accessed":"2026-08-27"},{"id":"iherb_sg","url":"https://sg.iherb.com/c/calcium","label":"iHerb Singapore — category page Calcium (Minerals), default order, 414 results","quote":"California Gold Nutrition, Magnesium Chelate with Calcium … 21st Century, Calcium Magnesium Zinc + D3 … Life Extension, Bone Restore, Calcium Supplement with Vitamin K2 … Nature's Bounty, Calcium Magnesium Zinc with Vitamin D3 … NOW Foods, Calcium & Magnesium, 250 Tablets","accessed":"2026-08-27"},{"id":"nih_ods_iron_con","url":"https://ods.od.nih.gov/factsheets/Iron-Consumer/","label":"NIH ODS — Iron Fact Sheet for Consumers (updated August 17, 2023) — Does iron interact with medications or other dietary supplements?","quote":"Calcium might interfere with iron absorption. Taking calcium and iron supplements at different times of the day might prevent this problem.","accessed":"2026-08-29"}],"brand_certs":null,"updated_at":"2026-08-29T16:16:14.713299+08:00"},"disclaimer":"kozen-x is not a medical device and does not give medical advice. it lists what published sources have written down. absence of a record is not the same as safe."}