In case it matters, this is the mineral formula I use:
Calcium (from microcrystalline hydroxyapatite) 600 mg 60%
Potassium (from potassium citrate) 99 mg 3%
Vitamin C (as ascorbic acid) 250 mg 417%
Vitamin D (as D3, cholecalciferol) 1800 IU 450%
Vitamin K (as K2, MK-7/menaquinone-7) 80 mcg 99%
Magnesium (from dimagnesium malate) 300 mg 75%
Zinc (from zinc monomethionine) 12 mg 80%
Copper (from copper gluconate) 1200 mcg 60%
Manganese (from manganese citrate) 2 mg 100%
Microcrystalline hydroxyapatite 2727 mg †
Boron (from boron citrate)
Yes. In most cases, food based vitamins and minerals are more absorbable than supplements because the food based nutrients exist as part of a food complex. In other words, they are contained within a matrix of proteins, fats and carbohydrates; they are part of organic complexes that are bodies readily recognize as food. Whereas in supplements, the nutrients are usually isolated or chelated (minerals attached to an amino acid). Some minerals are even given in inorganic form, like magnesium oxide or zinc oxide.
This is not to say that supplements do not have their place if your overall diet is lacking, but for the most part food based nutrients will always be more absorbable than non-food based nutrients.
If you like bok-choy, that's a great source of calcium, and also helps in calcium absorption if you don't want to do milk/supplements. http://www.livestrong.com/article/32008-foods-absorb-calcium/
Once, and only once, I took some cal mag supplements. I got a kidney stone. I started researching and a lot of people do get kidney stones when taking calcium in pill form. Be careful. I eat dairy, especially raw milk and raw milk kefir, and I have never again had a stone. You couldn't pay me to take a pill with calcium in it. My bones are in great shape.