The food-composition numbers in this post are essentially correct. Cleveland Clinic lists roasted almonds at 80 mg of magnesium per ounce and hulled roasted pumpkin seeds at 150 mg per ounce. USDA-derived tables put roasted pumpkin seed kernels at about 550 mg per 100 g, which works out to roughly 154 mg per ounce, and unsweetened cocoa powder at about 499 mg per 100 g, or roughly 27 mg per tablespoon. The post's stated "150-160mg per ounce" for pumpkin seeds is accurate.

The claim that magnesium is involved in over 300 reactions traces to a real authoritative source. NIH states that magnesium is a cofactor in more than 300 enzyme systems that regulate diverse biochemical reactions in the body, including protein synthesis, muscle and nerve function, blood glucose control, and blood pressure regulation.

Where the post breaks down is on absorption and on the "waste of money" conclusion. NIH states that in general, approximately 30% to 40% of the magnesium obtained from food and beverages is absorbed by the body. Nuts, seeds and cacao are all high in phytate, and phytate has been shown to decrease magnesium absorption by up to 60% in a dose dependent manner . Milligrams on a label are not the same as milligrams absorbed, and this cuts against the "delivers the same mineral" framing rather than supporting it.

NIH also identifies specific populations for whom food alone is often not sufficient. Certain groups are more likely than others to have magnesium inadequacy, including people with gastrointestinal diseases, type 2 diabetes, or alcohol dependence, and older adults. Magnesium inadequacy can occur when intakes fall below the RDA but are above the amount required to prevent overt deficiency.

Long-term use of proton-pump inhibitors for three months or longer may increase the risk of hypomagnesemia, and high doses of furosemide and some thiazide diuretics taken for extended periods may interfere with magnesium reabsorption in the kidneys and result in magnesium depletion. For these groups, supplementation is a legitimate clinical tool, not a waste of money.

The post's own claimed benefits of supplementation are also weakly evidenced. On sleep, a systematic review and meta-analysis identified only three randomized controlled trials in 151 older adults, all at moderate-to-high risk of bias, with outcomes supported by low to very low quality evidence, and concluded that the quality of the literature is substandard for physicians to make well-informed recommendations . Another review found an association between magnesium status and sleep quality in observational studies, while the randomized clinical trials showed an uncertain association between magnesium supplementation and sleep disorders . The post asserts that food-based magnesium "supports muscle relaxation, better sleep, and more consistent energy," which is a stronger claim than the trial evidence supports for magnesium in any form.