Calcium d-Glucarate

non-nutrient/non-botanicalD-glucarate(1-)

What is it

Calcium d-glucarate is the calcium salt of d-glucaric acid, a compound found naturally in fruits and vegetables such as oranges, apples, broccoli, and Brussels sprouts. It is marketed as a supplement primarily for its potential to support estrogen and toxin metabolism via inhibition of beta-glucuronidase.

How it works

Once absorbed, calcium d-glucarate is converted to d-glucaro-1,4-lactone, a compound that inhibits the enzyme beta-glucuronidase. Beta-glucuronidase, produced by gut bacteria and tissue cells, can cleave the glucuronide groups added by the liver to estrogen, xenobiotics, drugs, and other compounds during Phase II detoxification. When beta-glucuronidase splits these conjugates in the gut, the freed compounds can be reabsorbed (enterohepatic recirculation) rather than excreted. By inhibiting this enzyme, calcium d-glucarate theoretically increases the elimination of estrogens and various conjugated toxins, supporting the body's natural detoxification. Most of the evidence for these mechanisms comes from animal studies, including chemopreventive effects in rodent models of breast, colon, and lung cancers. Human clinical evidence is limited to small pilot studies and indirect data.

Evidence for 4 uses

AI-assisted evidence assessment — talk to your doctor before relying on any single supplement.

Estrogen metabolism support

Grade C

Moderate evidence

Mechanistic studies suggest calcium d-glucarate can lower serum estrogen by promoting excretion through reduced enterohepatic recirculation. Small human studies show changes in urinary estrogen metabolites. Whether this translates to meaningful clinical effects (e.g., breast cancer risk reduction) is not yet established.

Detoxification support

Grade D

Mixed evidence

Animal studies show enhanced excretion of various xenobiotics and pollutants. Direct evidence in humans for specific detoxification benefits is limited. Marketing claims often outpace clinical data.

Cholesterol

Grade D

Mixed evidence

Some small studies suggest possible modest effects on lipid profiles via altered bile acid metabolism. Evidence is preliminary.

Hormone-sensitive cancer prevention (animal data)

Grade F

Limited evidence

Calcium d-glucarate reduced incidence of mammary, colon, and lung tumors in rodent chemical-carcinogenesis models. Human clinical evidence is not yet sufficient to support clinical recommendations.

1 commercial form

Calcium d-glucarate tetrahydrate

Standard supplement form; converts to active d-glucaro-1,4-lactone in the body.

The form found in nearly all retail products. Inexpensive and stable.

Dosage

There is no RDA. Common supplement doses are 500-3,000 mg/day, typically split across 2-3 doses. Studies in humans have used 1.5-9 g/day. No UL is established; the compound is considered well-tolerated. The DSLD shows calcium d-glucarate in over 50,000 supplement labels.

When and how to take it

Take with food to support absorption and reduce GI upset. Splitting the daily dose into 2-3 administrations spread throughout the day appears to maintain more consistent beta-glucuronidase inhibition. Separate by at least 2 hours from thyroid medication or fluoroquinolone/tetracycline antibiotics due to calcium interactions.

Food sources

Food	Amount	%DV
Oranges (1 medium)	Naturally contains glucaric acid (mg amounts)	—
Broccoli (1 cup, raw)	Notable source	—
Brussels sprouts (1 cup)	Notable source	—
Apples (1 medium)	Modest amounts	—
Grapefruit (1/2 medium)	Notable source	—
Cherries (1 cup)	Modest amounts	—

Safety

Calcium d-glucarate appears well-tolerated in human studies, with mild and uncommon side effects (occasional GI upset, headache). Long-term safety data at higher doses are limited. The calcium component contributes modestly to total calcium intake and is unlikely to be a problem unless very high doses are combined with other calcium sources.

Who should be cautious

Avoid in pregnancy and lactation due to insufficient safety data. Use caution if taking oral contraceptives, hormone replacement therapy, or medications metabolized via glucuronidation. People on tamoxifen or other estrogen-modulating therapies should consult a clinician. Generally well-tolerated otherwise.

Interactions

Because calcium d-glucarate may accelerate clearance of compounds normally conjugated and reabsorbed via the gut, it could theoretically reduce levels of certain medications, including oral contraceptives, hormone therapy, and other drugs that undergo glucuronidation and enterohepatic recirculation. Caution with hormone-sensitive prescriptions. The calcium portion can interact with some antibiotics (tetracyclines, quinolones) and thyroid hormone if taken simultaneously.

Frequently asked questions

Does calcium d-glucarate lower estrogen?⌄

Mechanistic and small human studies suggest it can increase elimination of estrogen by reducing reabsorption in the gut. Whether this leads to meaningful clinical benefits in hormone balance or cancer prevention is not yet established.

Can it interfere with my birth control?⌄

Possibly, in theory. Oral contraceptive hormones undergo glucuronidation and enterohepatic recirculation, which calcium d-glucarate could disrupt. There are no specific contraceptive failures documented, but caution and clinician input are wise.

Is calcium d-glucarate the same as glucosamine?⌄

No. Calcium d-glucarate is a glucuronidation-related compound. Glucosamine is an amino sugar used for joint health. The names sound similar but they have completely different roles.

How long until I notice anything?⌄

Most users do not feel acute effects since the proposed benefits (altered hormone or toxin metabolism) are not subjectively obvious. Clinical research has typically measured biochemical changes over weeks to months.

Is it safe to take long-term?⌄

Short-term studies show good tolerability. Long-term safety at higher doses is not well-characterized. Most users cycle or use it at modest doses.

References

Calcium d-glucarate review — PubMed / Altern Med Rev link
D-glucaric acid - Wikidata — Wikidata link

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Disclaimer: These statements have not been evaluated by the FDA. This page is educational, not a substitute for personalized medical advice. Evidence grades are AI-assisted assessments — talk to your doctor before starting any new supplement, especially if you're pregnant, breastfeeding, on medications, or managing a chronic condition.