it's a sweet deal.
these days i can actually access private testing via an online vendor where i am too, but they don't offer an affordable $22 serum mag option like life extension. just a pricy rbc mag test. and if i did happen to want an rbc mag test, life extension offers it for $88 whereas here i'd have to pay over $120. so the options and the pricing are both sucky via this local vendor.
$22 is pretty reasonable to find out where you sit in the range for serum mag - low normal like ms patients and others with various chronic illnesses, or high normal like healthy controls. i like how the test description specifies that magnesium "helps maintain normal muscle and nerve function"
re normal range: i like this study
https://www.ajol.info/index.php/thrb/ar ... iew/120470 in which the reference range for healthy controls was 0.81-1.29 mmol/L vs a typical reference range 0.65-1.05 (i've seen 0.7-1.1 used locally, range can vary depending which lab you use, which study you're reading, etc). i really like its mention of 2.0 mmol/L as the low end of hypermagnesemia.
another recent fave:
Perspective: The Case for an Evidence-Based Reference Interval for Serum Magnesium: The Time Has Come
http://advances.nutrition.org/content/7/6/977.short
The 2015 Dietary Guidelines Advisory Committee indicated that magnesium was a shortfall nutrient that was underconsumed relative to the Estimated Average Requirement (EAR) for many Americans.
Approximately 50% of Americans consume less than the EAR for magnesium, and some age groups consume substantially less. A growing body of literature from animal, epidemiologic, and clinical studies has demonstrated a varied pathologic role for magnesium deficiency that includes electrolyte, neurologic, musculoskeletal, and inflammatory disorders; osteoporosis; hypertension; cardiovascular diseases; metabolic syndrome; and diabetes. Studies have also demonstrated that magnesium deficiency is associated with several chronic diseases and that a reduced risk of these diseases is observed with higher magnesium intake or supplementation. Subclinical magnesium deficiency can exist despite the presentation of a normal status as defined within the current serum magnesium reference interval of
0.75โ0.95 mmol/L. This reference interval was derived from data from NHANES I (1974), which was based on the distribution of serum magnesium in a normal population rather than clinical outcomes. What is needed is an evidenced-based serum magnesium reference interval that reflects optimal health and the current food environment and population. We present herein data from an array of scientific studies to support the perspective that subclinical deficiencies in magnesium exist, that they contribute to several chronic diseases, and that adopting a revised serum magnesium reference interval would improve clinical care and public health.
revisiting the neuro's comment re spasticity being too severe for a nutritional deficiency, perhaps he's not read the literature on magnesium deficiency induced tetanus and the use of magnesium to treat both dietary and infectious tetanus.
The Magnesium-Deficiency Tetany Syndrome in Man (1960)
https://www.ncbi.nlm.nih.gov/pubmed/13840893
excerpt: "When first seen, all the patients had tetany manifested by either spontaneous carpopedal spasm or positive Chvostek and Trousseau signs. In addition, 3 had generalized convulsions, and in 2 these were the initial manifestations of the disease. Athetoid motions of the extremities also occurred in 4 patients. ... The serum magnesium concentration of all 5 patients was markedly depressed when tetany was maximal, ranging from 0.60 to 1.33 milliequiv. per liter.
***(JL edit: converted, that's 0.3-.0.665 mmol/l - note that the upper end of this range would be characterized by some as 'normal' ie
magnesium deficiency induced tetany AND 'normal' serum mag at the same time)***.
All patients were treated with intramuscular injections of magnesium sulfate (MgSO4ยท7H2O), 2 to 4 ml. of a 50 per cent solution (1 to 2 gm.) every four hours. Concomitant with a rise of the concentration of magnesium in the serum to normal or slightly elevated values, there was a prompt and dramatic relief of tetany. In 4 patients continuation of this therapy resulted in complete recovery, without recurrence of tetany."
Magnesium as first line therapy in the management of tetanus: a prospective study of 40 patients (2002)
http://onlinelibrary.wiley.com/doi/10.1 ... 8_6.x/full