content: I really like the availability of a calcium/magnesium supplement in powder form. And I am sure KAL does a fine job in quality testing. I give it four stars only because you must be very careful with the dosage. I used their recommendation for a few weeks and wound up missing several days of work with terrible diarhea. After taking several weeks away, I started again with half the dosage, and have had no problems.I recommend taking this conjunction with a good vitamin D3/K2 supplement.