# Selenium Citrate

**Canonical URL:** https://ingredients.hermeticasuperfoods.com/ingredients/selenium-citrate
**Data Source:** Hermetica Superfoods Ingredient Encyclopedia
**Updated:** 2026-04-04
**Evidence Score:** 2 / 10
**Category:** Mineral
**Also Known As:** Selenious acid citrate complex, Citric acid selenium salt, Selenium(IV) citrate, Chelated selenium citrate, Organic selenium citrate, Se-citrate

## Overview

Selenium citrate is a chelated form of selenium bound to citric acid, designed to enhance mineral absorption and bioavailability compared to inorganic selenium salts. It exerts its primary effects by serving as a precursor for selenoprotein synthesis, including [glutathione](/ingredients/condition/detox) peroxidases and thioredoxin reductases, which are critical [antioxidant](/ingredients/condition/antioxidant) and redox-regulatory enzymes.

## Health Benefits

• General selenium support for [antioxidant](/ingredients/condition/antioxidant) function (evidence quality: theoretical based on selenium's role in selenoproteins, no citrate-specific trials found) • Potential [thyroid](/ingredients/condition/hormonal) support (evidence quality: based on general selenium research, not citrate-specific) • Possible [immune system](/ingredients/condition/immune-support) support (evidence quality: general selenium evidence exists, no citrate-specific studies identified) • May support cellular protection through [glutathione](/ingredients/condition/detox) peroxidase activity (evidence quality: mechanistic understanding of selenium, not tested for citrate form) • Potentially enhanced absorption compared to inorganic selenium (evidence quality: theoretical based on citrate's role as molecular shuttle)

## Mechanism of Action

Selenium citrate dissociates in the gastrointestinal tract, releasing selenium ions that are incorporated into selenocysteine, the 21st amino acid encoded by UGA codons in selenoprotein mRNA. This selenocysteine is then integrated into at least 25 known human selenoproteins, including [glutathione](/ingredients/condition/detox) peroxidase 1-4 (GPx1-4), which neutralize hydrogen peroxide and lipid hydroperoxides, and thioredoxin reductase (TrxR), which regenerates thioredoxin to maintain cellular redox balance. Additionally, selenoprotein P serves as the primary selenium transport protein in plasma, while iodothyronine deiodinases (DIOs 1-3) require selenium to catalyze the conversion of thyroxine (T4) to the active triiodothyronine (T3).

## Clinical Summary

No peer-reviewed clinical trials have been conducted specifically on selenium citrate as a distinct form; available evidence is extrapolated from research on other selenium forms including selenomethionine and sodium selenite. The SELECT trial (n=35,533) and NPC trial (n=1,312) examined selenium supplementation broadly, with mixed outcomes on cancer prevention and no definitive conclusions applicable to the citrate form. Studies using selenomethionine at 200 mcg/day have demonstrated measurable increases in plasma GPx activity and selenoprotein P levels, outcomes that selenium citrate may theoretically replicate given similar elemental selenium delivery. Overall, the evidence base for selenium citrate specifically is theoretical and preclinical, warranting cautious interpretation of any claimed benefits beyond general selenium repletion in deficient individuals.

## Nutritional Profile

Selenium citrate is a mineral supplement providing elemental selenium complexed with citric acid. Key nutritional and biochemical details: **Elemental Selenium Content:** Typically provides approximately 50–200 mcg of elemental selenium per dose depending on formulation; selenium citrate has a molecular weight where selenium constitutes roughly 35–40% of the total compound weight (selenium MW 78.96 g/mol bound to citrate anion C₆H₅O₇³⁻, MW ~189.1 g/mol; approximate complex MW ~270–320 g/mol depending on stoichiometry and hydration state). **Bioactive Role:** Selenium serves as a critical cofactor incorporated into 25+ selenoproteins including [glutathione](/ingredients/condition/detox) peroxidases (GPx1–GPx4), thioredoxin reductases (TrxR1–TrxR3), iodothyronine deiodinases (DIO1–DIO3), and selenoprotein P (SELENOP, the primary selenium transport protein). **Bioavailability Notes:** Selenium citrate is an organic selenium salt expected to have moderate-to-good aqueous solubility due to the citrate moiety, potentially enhancing gastrointestinal absorption compared to inorganic forms like sodium selenite. However, direct bioavailability studies comparing selenium citrate to selenomethionine (the most bioavailable organic form, ~90% absorption) or sodium selenite (~50–60% absorption) are lacking in published literature. Citrate may facilitate absorption via enhanced solubility at intestinal pH. Estimated absorption is likely in the 60–80% range based on analogous organic selenium salts, though this remains unconfirmed by clinical pharmacokinetic data. **Micronutrient Context:** Contains no significant macronutrients (protein, fat, carbohydrate, fiber), no vitamins, and no other minerals beyond selenium. The citrate component contributes negligible caloric value (<1 kcal per dose). **RDA Reference:** The recommended dietary allowance for selenium is 55 mcg/day for adults (US/EU), with a tolerable upper intake level (UL) of 400 mcg/day. Most selenium citrate supplements deliver 100–200 mcg per serving. **No additional bioactive compounds** beyond elemental selenium and the citrate carrier are present in pure selenium citrate formulations.

## Dosage & Preparation

No clinically studied dosage ranges are specified for selenium citrate in any form (extract, powder, or standardized). General selenium supplementation guidelines exist but lack form-specific guidance for citrate. Consult a healthcare provider before starting any new supplement.

## Safety & Drug Interactions

Selenium toxicity (selenosis) can occur at chronic intakes exceeding 400 mcg/day, presenting with symptoms including hair loss, nail brittleness, garlic breath odor, peripheral neuropathy, and gastrointestinal disturbance. Selenium supplementation may interact with anticoagulants such as warfarin by influencing vitamin K-dependent clotting factor synthesis, and may reduce the efficacy of certain chemotherapeutic agents including cisplatin due to its [antioxidant](/ingredients/condition/antioxidant) properties. Individuals taking [thyroid](/ingredients/condition/hormonal) medications such as levothyroxine should exercise caution, as selenium directly modulates T4-to-T3 conversion via iodothyronine deiodinases. Selenium supplements are generally not recommended during pregnancy above the established RDA of 60 mcg/day without medical supervision, as both deficiency and excess are associated with adverse fetal outcomes.

## Scientific Research

No specific human clinical trials, RCTs, or meta-analyses on selenium citrate alone were identified in the research. Studies typically evaluate other selenium forms like selenomethionine or yeast-bound selenium, making it impossible to attribute specific clinical outcomes to the citrate form.

## Historical & Cultural Context

No historical or traditional medicine uses are documented for selenium citrate, as it is a modern synthetic compound without ties to traditional systems like Ayurveda, TCM, or folk medicine. Elemental selenium itself has no noted traditional context in available sources.

## Synergistic Combinations

Vitamin E, Vitamin C, Zinc, Iodine, N-Acetyl Cysteine

## Frequently Asked Questions

### What is selenium citrate and how is it different from other selenium supplements?

Selenium citrate is selenium chelated to citric acid, which is theorized to improve gastrointestinal absorption compared to inorganic forms like sodium selenite or sodium selenate. Unlike selenomethionine, which is organically bound and incorporated directly into proteins in place of methionine, selenium citrate must first dissociate before selenium undergoes metabolic conversion to selenocysteine. No head-to-head bioavailability trials comparing selenium citrate to selenomethionine have been published as of current literature.

### How much selenium citrate should I take per day?

The recommended dietary allowance (RDA) for selenium in adults is 55 mcg/day, with a tolerable upper intake level (UL) set at 400 mcg/day by the National Institutes of Health. Most selenium supplements, including selenium citrate products, are dosed between 100-200 mcg elemental selenium per day for general health support. Doses above 400 mcg/day risk selenosis, and no specific dosing protocol has been established for the citrate form independent of general selenium guidelines.

### Does selenium citrate support thyroid health?

Selenium is an essential cofactor for the iodothyronine deiodinase enzymes (DIO1, DIO2, DIO3) that convert the prohormone thyroxine (T4) into the metabolically active triiodothyronine (T3). Clinical trials using 200 mcg/day of sodium selenite in autoimmune thyroiditis patients (Hashimoto's) have shown reductions in thyroid peroxidase antibody (TPO-Ab) titers by approximately 40-50% over 3-6 months. These benefits are attributed to selenium broadly, and whether selenium citrate replicates this effect at equivalent elemental doses has not been directly tested.

### Is selenium citrate safe to take with medications?

Selenium supplementation carries several known drug interaction risks: it may potentiate bleeding when combined with anticoagulants like warfarin due to its influence on vitamin K metabolism, and it can reduce the cytotoxic efficacy of platinum-based chemotherapy drugs such as cisplatin by mitigating oxidative stress. Statins and niacin combined with antioxidant supplements including selenium have shown attenuated HDL-raising effects in some cardiovascular trials. Always consult a healthcare provider before combining selenium citrate with prescription medications, particularly thyroid hormones, anticoagulants, or cancer therapies.

### What are the signs of selenium deficiency that selenium citrate might address?

Selenium deficiency manifests as reduced glutathione peroxidase activity, leading to increased oxidative stress, compromised immune cell proliferation, and impaired thyroid hormone conversion. Clinical deficiency syndromes include Keshan disease (a cardiomyopathy endemic to low-selenium regions of China) and Kashin-Beck disease (an osteoarthropathy), though these are rare outside of severely selenium-poor geographic areas or total parenteral nutrition patients. Subclinical deficiency, defined as serum selenium below approximately 70-80 mcg/L, is more common and associated with reduced selenoprotein P levels, which selenium citrate supplementation could theoretically normalize.

### How does selenium citrate absorption compare to other selenium forms like selenomethionine?

Selenium citrate is an inorganic form that relies on active absorption in the intestines, while selenomethionine (organic form) may be absorbed through both active and passive mechanisms, potentially offering superior bioavailability. Limited direct comparative studies exist specifically evaluating selenium citrate versus selenomethionine in humans, making it difficult to definitively state which form absorbs better. The citrate chelation may enhance mineral uptake compared to inorganic selenite, though individual absorption can vary based on digestive health and dietary factors.

### Is selenium citrate safe during pregnancy and breastfeeding?

Selenium is essential during pregnancy and lactation for fetal development and thyroid function, with an adequate intake of 60 mcg daily recommended for pregnant women. However, selenium citrate supplementation during pregnancy should only be used under healthcare provider guidance, as excessive selenium intake (above 400 mcg daily) may pose risks to fetal development. Most prenatal supplements contain appropriate selenium levels, and food-based sources are generally safer than additional supplementation without medical supervision.

### What clinical evidence supports selenium citrate's antioxidant benefits compared to general selenium research?

While selenium is well-established as a cofactor in selenoprotein enzymes with antioxidant properties, specific clinical trials comparing selenium citrate to placebo are limited and do not demonstrate unique benefits beyond general selenium supplementation. Most antioxidant evidence for selenium comes from observational studies and research on organic forms like selenomethionine rather than inorganic citrate compounds. To make evidence-based claims about selenium citrate specifically, more controlled human studies directly evaluating this form would be needed.

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*Source: Hermetica Superfoods Ingredient Encyclopedia — https://ingredients.hermeticasuperfoods.com*
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