chemistry

Magnesium citrate

Magnesium citrate is a chemistry topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Magnesium citrate rather than just read about it. In short: Magnesium citrates are metal-organic compounds formed from citrate and magnesium ions. They are salts.

Key takeaways

Magnesium citrate belongs to chemistry; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Magnesium citrate to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Magnesium citrate from memory before moving on to harder problems.

Reference excerpt

Magnesium citrates are metal-organic compounds formed from citrate and magnesium ions. They are salts. One form is the 1:1 magnesium preparation in salt form with citric acid in a 1:1 ratio (1 magnesium atom per citrate molecule). It contains 11.33% magnesium by weight. Magnesium citrate (sensu lato) is used medicinally as a saline laxative and to empty the bowel before major surgery or a colonoscopy. It is available without a prescription, both as a generic and under various brand names. It is also used in the pill form as a magnesium dietary supplement. As a food additive, magnesium citrate is used to regulate acidity and is known as E number E345.

Structures The structures of solid magnesium citrates have been characterized by X-ray crystallography. In the 1:1 salt, only one carboxylate of citrate is deprotonated. It has the formula Mg(H2C6H5O7)2. The other form of magnesium citrate has the formula Mg(HC6H5O7)(H2O)2, consisting of the citrate dianion (two of citric acid's carboxyl groups are deprotonated). Thus, it is clear that name "magnesium citrate" is ambiguous and sometimes may refer to other salts such as trimagnesium dicitrate which has a magnesium:citrate ratio of 3:2, or monomagnesium dicitrate with a ratio of 1:2, or a mix of two or three of the salts of magnesium and citric acid.

Mechanism of action Magnesium citrate works by attracting water through the tissues by a process known as osmosis. Once in the intestine, it can attract enough water into the intestine to induce defecation. The additional water stimulates bowel motility. This means it can also be used to treat rectal and colon problems. Magnesium citrate functions best on an empty stomach, and should always be followed with a full (eight-ounce or 250 ml) glass of water or juice to help counteract water loss and aid in absorption. Magnesium citrate solutions generally produce bowel movement in one-half to three hours.

Use and dosage The maximum upper tolerance limit (UTL) for magnesium in supplement form for adults is 350 mg of elemental magnesium per day, according to the National Institutes of Health (NIH) In addition, according to the NIH, total dietary requirements for magnesium from all sources (in other words, food and supplements) is 320–420 mg of elemental magnesium per day, though there is no UTL for dietary magnesium.

Laxative Magnesium citrate is used as a laxative agent.

Magnesium deficiency treatment Although less common, as a magnesium supplement the citrate form is sometimes used because it is believed to be more bioavailable than other common pill forms, such as magnesium oxide. But, according to one study, magnesium gluconate was found to be marginally more bioavailable than even magnesium citrate. Potassium-magnesium citrate, as a supplement in pill form, is useful for the prevention of kidney stones.

Side effects Magnesium citrate is generally not a harmful substance, but care should be taken by consulting a healthcare professional if any adverse health problems are suspected or experienced. Extreme magnesium overdose can result in serious complications such as slow heartbeat, low blood pressure, nausea, drowsiness, etc. If severe enough, an overdose can even result in coma or death. However, a moderate overdose will be excreted through the kidneys, unless one has serious kidney problems. Rectal bleeding or failure to have a bowel movement after use could be signs of a serious condition.

See also ATC code A12 Magnesium aspartate

References

External links Saline laxatives. MedicineNet. Magnesium citrate Patient Advice. Drugs.com. Magnesium glycinate vs. magnesium citrate – formulation comparison

Illustrations

Worked examples

Example 1 — a first encounter with Magnesium citrate

Start with the simplest possible case. Write down what Magnesium citrate claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In chemistry, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Magnesium citrate before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Magnesium citrate ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Magnesium citrate

In research: Magnesium citrate appears in chemistry research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Magnesium citrate in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Magnesium citrate is common in secondary-school and first-year university syllabi. It links to neighbouring topics Antiarrhythmic agents, Antidepressants, Antispasmodics, so understanding it makes those chapters shorter.
In everyday life: Look for Magnesium citrate outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Magnesium citrate in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Magnesium citrate means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Magnesium citrate out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Magnesium citrate in simple terms?

Magnesium citrates are metal-organic compounds formed from citrate and magnesium ions. They are salts.

Why does Magnesium citrate matter?

Because it connects several chemistry ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Magnesium citrate?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Magnesium citrate.