From the Guidelines
Magnesium oxide is the best type of magnesium to take, as it has been shown to increase the number of complete spontaneous bowel movements (CSBMs) per week and stool-based bowel movements (SBMs) per week, with minimal difference in diarrhea leading to treatment dose change or discontinuation compared to placebo, as evidenced by a 2023 study published in Gastroenterology 1. When considering the best type of magnesium supplement, it's essential to look at the most recent and highest quality studies.
- The study published in Gastroenterology in 2023 found that magnesium oxide (MgO) increased the number of CSBMs per week (MD 4.29,95% CI 2.93–5.65) and SBMs per week (MD 3.59,95% CI 2.64–4.54) compared to placebo 1.
- Additionally, participants treated with MgO achieved a higher treatment response compared to placebo (RR 3.93,95% CI 2.04–7.56) and had better quality-of-life scores as measured by PAC-QOL (MD 16.23,95% CI 11.44–21.01) and better stool consistency based on the Bristol Stool Form Scale (MD 1.89,95% CI 1.44–2.33) 1.
- Another study published in Gastroenterology in 2023 also suggests the use of magnesium oxide over management without magnesium oxide, with a conditional recommendation and very low certainty of evidence 1.
- It's also important to note that the bioavailability and clinical efficacy of other formulations of magnesium, such as citrate, glycinate, lactate, malate, and sulfate, for chronic idiopathic constipation (CIC) are unknown, and only MgO has been evaluated in randomized controlled trials (RCTs) 1.
- However, it's crucial to consider the potential risks and limitations, such as the small number of clinical trials and included participants with CIC, all trials being conducted in Japan, formulations other than MgO not being evaluated, the dose of MgO used in trials being higher than that typically used in clinical practice, and no long-term effectiveness or harms data being available 1.
- People with kidney disease should consult their doctor before taking any magnesium supplement, as hypermagnesemia is more likely to occur in individuals with significant renal impairment 1.
From the FDA Drug Label
ACTIVE INGREDIENT Magnesium Glycinate: ~93.75% Active Ingredient Magnesium citrate 1.745g per fl oz The best type of magnesium to take is not explicitly stated in the FDA drug labels.
- Magnesium Glycinate and Magnesium Citrate are two types of magnesium supplements mentioned in the labels 2 and 3, respectively. However, the FDA drug label does not provide a direct comparison or recommendation of one type over the other.
From the Research
Types of Magnesium
- There are various forms of magnesium, including inorganic and organic formulations, with differing bioavailability 4
- Inorganic formulations appear to be less bioavailable than organic ones, and the percentage of absorption is dose dependent 4
Bioavailability of Magnesium
- A systematic review compared the bioavailability of different forms of magnesium and found that all magnesium dietary supplements can maintain physiological levels in healthy people without prior deficit 4
- However, this cannot be assured in older people or those with illnesses or previous subphysiological levels 4
Effective Forms of Magnesium for Anxiety and Sleep
- While there is evidence to suggest that magnesium supplementation may be beneficial for anxiety and sleep, the most effective form and dosage are unclear due to the heterogeneity of the data and the small number of participants involved in most studies 5, 6
- Some studies suggest that supplemental magnesium is likely useful in the treatment of mild anxiety and insomnia, particularly in those with low magnesium status at baseline 6
Magnesium Requirements
- The estimated average requirements (EARs) for magnesium have been revised to account for rising body weights and data-derived variance, resulting in increased EARs for both men and women 7
- The recommended dietary allowances (RDAs) for magnesium have also been recalculated, with suggested increases of 16.5-65.5% for men and 23.5-65.5% for women 7