Magnesium supplement

Tanstaafl brought up the subject of Magnesium supplements in my Vitamin D post, but I thought I would separate this out as a new post.  I had not considered magnesium supplements before Tanstaafl's suggestion, but as I did some research, it seems that between 50% and 79% of Americans are magnesium deficient.  Magnesium is absorbed in the small instestine and colon, so anyone with colon issues (most all of us, I assume) is at risk of deficiency.  Also, alchohol consumption or PPI (prilosec and the like) consumption increases the risk of deficiency.  Lower magnesium rates are related to higher risk of cancer (perhaps about 11% higher) and magnesium also interacts favorably with Vitamin D and calcium absorbtion. 

Based on this, I have added a 400mg supplement to my regime and backed off calcium by one half.  I will not belabor this post with lots of information (including magnesium to calcium ratios) but will include a few links that I found interesting.  

* * *

Findings from this meta-analysis of prospective studies, including more than 8000 CRC cases, indicate that a high magnesium intake may provide a modest protection against CRC risk. The reduction in risk is 11% (95% CI, 0–21%) for the highest vs lowest category of magnesium intake and, on average, 5% (95%CI, 0–11%) for each additional 50mg/day increase in magnesium intake. The observed beneficial effect of magnesium intake against CRC appeared to be independent of calcium intake and restricted to colon cancer only.
https://www.nature.com/articles/ejcn2012135

The 1999–2000 National Health and Nutrition Examination Survey found 79% of U.S. adults have a magnesium intake below the Recommended Dietary Allowance [21]. Magnesium deficiency in Western societies has been linked to insulin resistance [22], [23], type II diabetes [24], [25], metabolic syndrome [26], coronary heart disease [27], colorectal cancer [28], and colorectal adenoma . . . increasing magnesium levels were associated with a lower likelihood of being diagnosed with high-grade prostate cancer. For example, magnesium levels in the highest tertile were associated with an approximate 48% reduction in risk (OR?=?0.52, (0.26, 1.02; p-trend?=?0.04). This association became stronger after additional control for calcium (OR?=?0.48 (0.24–0.96; p-trend?=?0.03) . . . Our finding indicates that higher blood magnesium levels are associated with a lower risk of high-grade prostate cancer. The lower ratio of calcium to magnesium was also associated with high-grade prostate cancer, suggesting the interaction between magnesium and calcium plays a role in the pathogenesis and progression of this disease to a more clinically relevant phase. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3081812/

It appears that too much or too little of either calcium or magnesium might not be beneficial and there may be an optimal range of human calcium and magnesium intake. . .
Thus, these findings showed no effect for a high dose of vitamin D alone or magnesium infusion alone; however, there was a substantial increase in serum 25(OH)D due to vitamin D supplementation with magnesium infusion.

Studies showed that a calcium to magnesium intake ratio <2.8 is critical for optimal health, supporting a long-held but non–evidence-based recommendation that the calcium to magnesium ratio should be close to 2. Increasing calcium intakes in the United States since 1977 have resulted in a calcium to magnesium ratio >3.0 since 2000, coinciding with increasing rates of T2D and colorectal cancer. US studies assessing oral magnesium therapy or dietary magnesium intakes showed beneficial effects of dietary magnesium in CVD, T2D, and cancers, although similar studies in populations with lower calcium to magnesium ratios (=1.7) reported the opposite, showing the impact that background dietary calcium and/or magnesium can have on studies of either calcium or magnesium alone. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4717874/

Everything you ever wanted to know about Magnesium and more: http://www.physiomics.eu/media/181616/de_baaij_magnesium_in_man.full.pdf