I have never heard of magnesium' effects wearing off, nor should there be any reason for it to. Likely you were so sleep deprived initially that you went in to a deeper sleep. And as your body has become more rested you are sleeping lighter.

"My questiion is, after taking minerals for awhile does the effect taper off. I find I'm still sleeping well but it's not the same as when I first started taking magnesium"

Yes you will see a diminished effect from using isolated elements such as magnesium, eventually you will throw your Ca/Mg ratios off balance and the positive effects will decrease as time goes on!
Minerals work synergistically with one another and to supplement with just one is not recommended!




Calcium and magnesium act synergistically in hundreds of reactions in the body, and they must both be respected and taken in balance. Magnesium is called, “the forgotten mineral” by some. For instance, as important as calcium is in muscle function, the contraction-relaxation phase cannot operate without magnesium. Bones also need healthy balances of both calcium and magnesium. Additionally, calcium is essential for healthy blood, it helps regulate heartbeat, eases insomnia, assists in blood clotting, plays a part in muscle growth and nerve transmission, aids in iron utilization, and regulates passage of nutrients in and out of cells. A National Institutes of Health panel reported that 1/2 of all Americans fall below the RDA in their consumption of calcium, and that was before the RDA increase from 800 to 1500 milligrams per day was suggested (NIH Committee, Nutrition Week 22:7, June 10, 1994). It is also estimated that Americans fall short in their consumption of magnesium, the balancing nutrient to calcium. Magnesium is associated with regulation of body temperature, it activates enzymes necessary for metabolism of carbohydrates and amino acids, stimulates the body's own production of HCl (hydrochloric acid), functions in lipid and protein metabolism (essential for rebuilding after injury), and serves as a cofactor for many energy metabolism enzymes. In fact, magnesium is so important in energy production, that, "Trials with magnesium have improved the well-being of patients (with chronic fatigue syndrome)" (Nippon-Rinsho 1992 Nov; 50(11):2679-83). Magnesium's function in protein metabolism and rebuilding after injury makes it useful in providing ligamental nutrient support. Older people may be able to improve their ability to metabolize glucose by taking magnesium supplements, and magnesium may be helpful as a supplement for diabetics (AJCN 1992; 55:1161-1167).

Calcium citrate, calcium aspartate, and calcium malate are highly absorbable forms of calcium. Since there are different amino acid carrier systems which transport minerals across the cell wall, these different forms of calcium take advantage of different carrier systems to ensure optimal absorption. Beware of over-the-counter antacids--they are not an absorbable calcium source! Calcium is not of any benefit to the body unless it is absorbed and utilized. Calcium needs an acidic environment for optimal absorption, whereas antacids buffer the hydrochloric acid (HCL) that is necessary to facilitate absorption.
Clinical Applications/Research

Clinical applications include muscle spasming (cramps), muscle tone, osteoporosis, faulty nerve transmission, anxiety, PMS, menstrual cramping, insomnia, blood clotting, iron absorption, heartbeat irregularities, hypertension, colon conditions, and chronic fatigue