Why Magnesium Citrate Is a Popular Choice After 50
Magnesium citrate is one of the most widely used forms of supplemental magnesium. It is formed by combining magnesium with citric acid, and research comparing magnesium forms has consistently shown it to have good bioavailability relative to inorganic forms such as magnesium oxide.
For adults over 50, magnesium citrate offers a practical advantage: it is well absorbed even in conditions of reduced gastric acid secretion, which becomes more common with age and especially with proton pump inhibitor use. This makes it a sensible choice when absorption efficiency is a priority.
Age-Related Need for Magnesium
Magnesium deficiency is more prevalent in older adults for several reasons. Dietary surveys indicate that many adults over 50 consume less than the recommended intake. Intestinal absorption declines with age, and the kidneys become less efficient at conserving magnesium. Use of diuretics, PPIs, and some diabetes medications further increases losses.
Consequences of chronically low magnesium status in older adults may include muscle cramps, fatigue, disturbed sleep, elevated blood pressure, and impaired bone health. Magnesium is a cofactor in vitamin D activation, so low magnesium can also limit the effectiveness of vitamin D supplementation.
How Magnesium Citrate Absorbs Differently
A crossover study comparing magnesium citrate with magnesium oxide found that urinary magnesium excretion — a proxy for absorbed magnesium — was significantly higher after magnesium citrate supplementation (Walker et al., 2003). Since urinary excretion reflects what was absorbed (excess beyond tissue needs is excreted), higher urinary output at equivalent doses suggests better absorption.
Magnesium oxide, by contrast, has low solubility and relatively poor absorption, though it has been used in high-dose laxative applications for this reason.
Dose and Safety
Typical supplemental doses of magnesium citrate range from 150–400 mg of elemental magnesium per day. Products at maxfit.ee include OstroVit Magnesium Citrate 200g Naturaalne, SELF Potassium Magnesium 120 vegan caps, 
SELF Magnesium Ultra Strength€17.90 In stock 90caps, and OstroVit Magnesium MAX + Vitamin 60tabs.
Note the distinction between the weight of the magnesium citrate salt and the elemental magnesium content — always check the label for the elemental amount per serving.
At high doses, magnesium citrate has a laxative effect due to its osmotic action in the gut. This is dose-dependent and usually resolves by reducing the dose or splitting it across the day. Starting at a lower dose and increasing gradually minimises this.
Interactions With Medication
The interaction profile for magnesium citrate mirrors that of magnesium in general:
- Antibiotics (tetracyclines, fluoroquinolones): Take at least 2 hours apart to avoid reduced antibiotic absorption.
- Bisphosphonates: Separate by at least 2 hours; these must be taken on an empty stomach, away from minerals.
- Diuretics: Loop diuretics increase magnesium losses; magnesium supplementation may be warranted and should be discussed with a doctor.
- Diabetes medications: Some evidence suggests magnesium supplementation may affect insulin sensitivity. Monitor blood glucose if diabetic.
When to Supplement
Magnesium citrate supplementation is particularly worth considering for older adults who:
- Take PPIs long-term
- Use diuretics
- Have poor dietary magnesium intake (below 300 mg/day from food)
- Experience unexplained muscle cramps or disrupted sleep
- Are supplementing with vitamin D and want to support its activation pathway
Magnesium supplementation is generally very safe. The main risks are loose stools at high doses and, rarely, hypermagnesaemia in people with severely impaired kidney function. Those with advanced kidney disease should consult a physician before supplementing.
FAQ
How does magnesium citrate compare with magnesium glycinate?
Both have good bioavailability. Glycinate is chelated with the amino acid glycine and tends to be very gentle on the gut — it is often the first recommendation for those who experience loose stools with citrate. Citrate tends to be more affordable and widely available. Both are appropriate for older adults.
Does magnesium citrate help with sleep after 50?
Magnesium plays a role in the regulation of GABA receptors and melatonin pathways. Some people report improved sleep with magnesium supplementation. The evidence is modest but consistent with the nutrient's known functions in nervous system regulation.
Can I take magnesium citrate every day?
Yes, ongoing daily supplementation is appropriate for those whose dietary intake is insufficient. Most people tolerate it well at doses up to 350–400 mg elemental magnesium per day from supplements.
References
Walker, A. F., Marakis, G., Christie, S., & Byng, M. (2003). Mg citrate found more bioavailable than other Mg preparations in a randomised, double-blind study. Magnesium Research, 16(3), 183–191. https://pubmed.ncbi.nlm.nih.gov/14596323/
Rude, R. K., Singer, F. R., & Gruber, H. E. (2009). Skeletal and hormonal effects of magnesium deficiency. Journal of the American College of Nutrition, 28(2), 131–141. https://pubmed.ncbi.nlm.nih.gov/19828898/
Baaij, J. H., Hoenderop, J. G., & Bindels, R. J. (2015). Magnesium in man: implications for health and disease. Physiological Reviews, 95(1), 1–46. https://doi.org/10.1152/physrev.00012.2014
