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Magnesium salts of citric acid

Also known as: Magnesium salts of citric acid, Magnesium citrate salt, Magnesium citrate malate, Magnesium citrate

Overview

Magnesium citrate is an organic salt formed by combining magnesium and citric acid, primarily used as a dietary supplement to increase magnesium intake. Unlike magnesium found naturally in foods, magnesium citrate is synthetically produced for supplementation. Its main applications include correcting magnesium deficiency, supporting cardiovascular health, improving bowel function due to its laxative properties, and potentially modulating mood disorders. It is highly regarded for its relatively high bioavailability compared to inorganic magnesium salts like magnesium oxide, meaning it is more readily absorbed and utilized by the body. It is water-soluble and exerts an osmotic laxative effect at higher doses. Research on magnesium citrate is moderate, with several randomized controlled trials and systematic reviews supporting its bioavailability and some clinical benefits, particularly in cardiovascular health and mood regulation. While good quality evidence exists, more large-scale, long-term studies are needed for comprehensive understanding.

Benefits

Magnesium citrate offers several evidence-based benefits, primarily due to its superior bioavailability. It shows significantly better absorption than magnesium oxide, leading to a maximal serum magnesium increase of about 23% in animal models and stable absorption in humans, making it effective for correcting magnesium deficiency. For cardiovascular health, supplementation has been linked to reductions in arterial stiffness, a crucial risk marker, with a decrease of 1.0 m/s potentially reducing cardiovascular event risk by 14%. In the realm of mood disorders, systematic reviews indicate that magnesium supplementation, including citrate forms, is associated with a statistically significant reduction in depressive symptoms, with an odds ratio of 0.84 (95% CI: 0.70–0.98). Additionally, magnesium citrate may enhance the antioxidant activity of immune cells and modulate inflammatory pathways. These benefits are particularly relevant for individuals with magnesium deficiency, those at risk for cardiovascular issues, or those experiencing mood disorders. The observed effects on arterial stiffness and mood are clinically significant, though effect sizes can vary. Cardiovascular benefits typically manifest over weeks to months of consistent use, as do mood improvements.

How it works

Magnesium citrate functions by increasing serum magnesium levels, which is crucial as magnesium acts as a cofactor in over 300 enzymatic reactions. These reactions are vital for regulating vascular tone, neurotransmitter release, and immune function. Its organic salt form and high solubility contribute to its efficient absorption in the gastrointestinal tract, making it more bioavailable than inorganic magnesium salts like magnesium oxide. Once absorbed, magnesium influences various body systems, including the cardiovascular system by modulating vascular tone, the nervous system by affecting neurotransmitter release, and the immune system by enhancing antioxidant activity. Specifically, magnesium modulates nitric oxide synthase (NOS2) and arginase-1 expression in monocytes, contributing to its antioxidant effects.

Side effects

Magnesium citrate is generally considered safe when consumed within recommended dosages. The most common side effect, occurring in over 5% of users, is diarrhea or loose stools. This is due to its osmotic laxative effect, where it draws water into the intestines. Less common side effects, affecting 1-5% of individuals, include abdominal cramping and nausea. Rarely, hypermagnesemia (excessively high magnesium levels in the blood) can occur, particularly in patients with pre-existing renal impairment, as their kidneys may not efficiently excrete excess magnesium. Magnesium citrate can interact with certain medications; it may reduce the absorption of some antibiotics, such as tetracyclines and fluoroquinolones, if taken concurrently. It is contraindicated in individuals with severe renal impairment or heart block without a pacemaker. Special caution is advised for elderly individuals and those with kidney disease due to their potentially reduced ability to excrete magnesium, increasing the risk of adverse effects.

Dosage

For correcting magnesium deficiency, a minimum effective dose of 200–300 mg of elemental magnesium daily is typically recommended. The optimal dosage range for general supplementation is 200–400 mg of elemental magnesium per day. Doses exceeding this range may increase the likelihood of experiencing laxative effects. The maximum safe dose from supplements for adults is generally considered to be up to 350 mg of elemental magnesium per day; higher doses should only be used under medical supervision. Magnesium citrate can be taken with or without food, and dividing the daily dose into multiple smaller administrations may improve tolerance and reduce gastrointestinal side effects. Magnesium citrate is preferred over magnesium oxide due to its superior absorption. Its absorption can be enhanced by adequate stomach acid and may be reduced by concurrent intake of phytates or calcium. No specific cofactors are required for its function, but a balanced intake of other electrolytes supports overall magnesium efficacy.

FAQs

Is magnesium citrate better absorbed than magnesium oxide?

Yes, studies consistently show that magnesium citrate has significantly higher bioavailability and absorption compared to magnesium oxide, making it a more effective form for supplementation.

Can magnesium citrate cause diarrhea?

Yes, magnesium citrate has an osmotic laxative effect, meaning it draws water into the intestines, which can lead to diarrhea or loose stools, especially at higher doses.

How long does it take to see benefits from magnesium citrate?

Benefits, particularly for cardiovascular health and mood improvement, typically begin to appear after several weeks to months of consistent daily supplementation.

Is magnesium citrate safe for long-term use?

Generally, magnesium citrate is safe for long-term use at recommended doses. However, caution is advised for individuals with renal impairment due to the risk of magnesium accumulation.

Does magnesium citrate improve mood?

Evidence from systematic reviews suggests that magnesium supplementation, including citrate forms, is associated with a modest but statistically significant reduction in depressive symptoms.

Research Sources

https://www.annexpublishers.com/articles/JNH/12101-In-vitro-and-In-vivo-Comparison-of-Marine-Magnesium-salts.pdf – This study compared marine magnesium salts, including citrate, in murine models and human monocytes. It found that magnesium citrate exhibited high and stable absorption, leading to a maximal serum magnesium increase of 23%. Furthermore, it demonstrated that magnesium citrate enhanced antioxidant activity in human monocytes, suggesting its potential benefits beyond simple magnesium delivery.
https://pmc.ncbi.nlm.nih.gov/articles/PMC6540466/ – This randomized clinical trial investigated the long-term effects of various magnesium forms, including citrate, on arterial stiffness in humans. The study concluded that magnesium citrate significantly reduced arterial stiffness, a key indicator of cardiovascular risk. It also highlighted magnesium citrate's superior bioavailability and effect size compared to other forms like magnesium oxide or sulfate.
https://pmc.ncbi.nlm.nih.gov/articles/PMC6034436/ – This systematic review and meta-analysis synthesized data from multiple randomized controlled trials on magnesium supplementation and mood disorders. The findings indicated a statistically significant association between magnesium treatment and a reduction in depressive symptoms, with an odds ratio of 0.84. The review supports the role of magnesium, including citrate forms, in mental health.