hi, i just started taking minocycline two days ago. yeah, take it with food b/c it might upset your stomach some. i dunno if you know this or not.. but wear sunscreen, lots and lots of sunscreen..! my face got pretty burned the first day but it's much better today.
as for calcium:
"be aware that antacids, calcium supplements, iron products, and laxatives containing magnesium interfere with minocycline, making it less effective. Take minocycline 1 hour before or 2 hours after antacids (including sodium bicarbonate), calcium supplements, and laxatives containing magnesium. Take minocycline 2 hours before or 3 hours after iron preparations and vitamin products that contain iron."
(got it from http://www.nlm.nih.gov/medlineplus/druginfo/medmaster/a682101.html)
i think that means just don't take the calcium close to when you take minocycline...
Minocycline (Minocin, Vectrin) may be taken on an empty stomach or with food. Milk and other dairy products should be avoided, unless otherwise directed by your doctor, as they may decrease the absorption of minocycline. Instructions regarding minocycline use may vary by manufacturer. If you need to take minocycline with milk, talk to your pharmacist to verify if your particular prescription should be taken with dairy products.
(got it from http://health.discovery.com/encyclopedias/reference/drug.jsp?drug=9781)
i think mashed potatoes would be ok unless that's all you were having for dinner or something
well, i hope that helps a bit and good luck!