given the level and the range at your local lab, 2.0 mg/dL appears to be a serum mag result and qualifies as low normal, a part of the range known to be associated with deficiency states.
some authors have proposed lower cutoffs from 2.2 to 2.3 mg/dL. the upper end of the normal range at my local lab, which i have seen published as a healthy controls *average* in research, is 2.7 mg/dL.
so, i would aim for a serum level of 2.3-2.7 mg/dL, and I would try really hard to get as much of that as possible from dietary sources.
i would recommend supplemental dosing of magnesium to suit your current serum mag status, plus your level of dietary intake, as well as your habitual intake of other factors that might have a positive or negative influence on absorption.
if your serum levels are below 2.3, i'd suggest a daily total intake of 600mg per day. once your levels are at least 2.3, you can aim for daily intakes from 300-400mg daily.
*if* we can assume your levels are currently about the same as in 2012. a good place to start could be to calculate your current dietary intake of mag, to see how close you are to 600mg. then you can work to boost dietary intake. and after that, you could supplement with mag glycinate to make up the balance.
list of healthy mag sources with serving sizes and mgs per serving:http://www.whfoods.com/genpage.php?tnam ... #foodchart
it's best to do as much as possible from a varied selection of magnesium rich foods, since these will have a better mix of co-factors as compared to isolated supplement products.
overall, to ensure absorption you could work to ensure as little interference as possible from:
- depleters such as physical stress, diuretics (eg caffeinated beverages, alcohol), and/or medications (such as proton pump inhibitors (PPIs));
- binders (such as gluten, phosphates);
- excessive intake of competitors (such as calcium above 1200mg per day.. twice daily mag (the commonly seen 2:1 ratio ) is a maximum, not a target).
hope that helps, sorry i can't give you a blanket recommendation other than the daily overall targets depending on whether you're looking to increase or maintain.. and even then, other than how you feel, you still need a bit of follow up testing to establish efficacy.. not the simplest thing in the world!
my approach: no meds so far - just nutrient-dense anti-inflammatory whole foods, and supplements where needed
info: www.whfoods.com, www.nutritiondata.com