Magnesium

    Written by:
    Brady Holmer, Thomas Solomon

    Fact-checked

    by:

    Marina Shkayeva, Louie Neri
    Last Updated: October 21, 2025

    Magnesium is an essential dietary mineral that is involved in energy production, nervous system function, blood pressure regulation, and blood glucose control. A lack of magnesium in the diet — which is common in modern societies — is associated with an increased risk of diabetes, cardiovascular disease, and other health conditions.

    Overview

    Dosage Information

    Formulation:

    Dosage forms of magnesium include oral preparations such as tablets, capsules, powders, liquids, and effervescent tablets as well as topical preparations.

    Magnesium supplements come in a variety of salt forms that differ in how well they’re absorbed (their bioavailability), the amount of elemental magnesium they provide, and their physiological effect. Common forms include magnesium oxide, magnesium citrate, magnesium glycinate, magnesium bisglycinate, and magnesium chloride.

    Which form of magnesium is best for increasing magnesium levels?

    Magnesium citrate is one of the most-studied forms of magnesium and consistently shows good bioavailability.[1] Magnesium chloride, magnesium gluconate, magnesium lactate, magnesium glycinate, and magnesium aspartate also appear to have good bioavailability.[2][1][3] On the other hand, magnesium oxide and magnesium carbonate have extremely poor absorption and aren’t recommended for the purpose of increasing magnesium levels in the body. They also have an increased risk of gastrointestinal side effects.[2]

    Oral bioavailability of various magnesium formulations

    Reference: Ranade et al. Am J Ther. 2001. [2]

    Although magnesium sulfate (Epsom salt) is often used in bath preparations to soothe achy and sore muscles, there’s a lack of evidence to support the transdermal (through the skin) absorption of magnesium.[4] A warm soak might be relaxing, but it’s not due to the magnesium.

    Range of dosages studied:

    Doses used in studies have ranged from 30 to 960 milligrams per day (mg/day) of elemental magnesium.

    Other Considerations:

    The recommended dietary allowance (RDA) of magnesium is the amount that should be consumed to meet the nutritional requirements of most people. It includes magnesium from all sources, including food, beverages, supplements, and medications. The tolerable upper intake level (UL) for magnesium only includes magnesium obtained from dietary supplements and medications. Supplement doses exceeding the UL are more likely to cause adverse effects.

    Magnesium RDA

    AGEMALEFEMALEPREGNANTLACTATING
    0–6 months30 mg*30 mg*——
    7–12 months75 mg*75 mg*——
    1–3 years80 mg80 mg——
    4–8 years130 mg130 mg——
    9–13 years240 mg240 mg——
    14–18 years410 mg360 mg400 mg360 mg
    19–30 years400 mg310 mg350 mg310 mg
    31–50 years420 mg320 mg360 mg320 mg
    >50 years420 mg320 mg——

    * Adequate intake (AI)
    Reference: Institute of Medicine. Magnesium (chapter 6 of Dietary Reference Intakes for Calcium, Phosphorus, Magnesium, Vitamin D, and Fluoride. The National Academies Press. 1997. DOI: 10.17226/5776)

    Magnesium UL

    AGEMALEFEMALEPREGNANTLACTATING
    0–12 months————
    1–3 years65 mg65 mg——
    4–8 years110 mg110 mg——
    >9 years350 mg350 mg350 mg350 mg

    Reference: Institute of Medicine. Magnesium (chapter 6 of Dietary Reference Intakes for Calcium, Phosphorus, Magnesium, Vitamin D, and Fluoride. The National Academies Press. 1997. DOI: 10.17226/5776)

    Frequently Asked Questions

    Update History

    Examine Database update

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