On one of the links - http://www.vitamins-nutrition.org/vitamins/calcium.html - from the BBC The Truth About Food site, it says: "Calcium is the mineral most likely to be deficient in the average diet. Let me repeat that. Calcium is the mineral most likely to be deficient in the average diet. Calcium deficiency is a condition in which we fail to receive or to metabolize an adequate supply of Calcium," and also: "Calcium helps keep the weight off. Research suggests that if you don't get enough calcium in your diet, you're likely to be overweight."
There are a number of reasons that overweight people in particular tend to be deficient in calcium. Overweight people suffer from sodium retention/salt sensitivity/fluid retention and sodium retention/salt sensitivity/fluid retention depletes the body of calcium and is the main reason for the calcium deficiency problem in overweight/obese people.
Here are two other very simple reasons:
1. Most fat people are ‘dieting’ most of the time – i.e. they are eating insufficient food for their body’s needs.2. Fat people are routinely advised to limit their intake of dairy food like milk because their advisors (wrongly) believe that milk is ‘fattening’.
And specifically it also means having a higher intake of calcium, especially, if possible, from dairy yoghurt. – It is also necessary to ensure sufficient vitamin D intake, as this is needed to metabolise the calcium. Insufficiency of vitamin D is quite common, as is widely reported, e.g. here - http://ods.od.nih.gov/factsheets/vitamind.asp
The best source of vitamin D is summer sunshine round about midday. - Go out then if you can, bare-armed, and soak up some summer sunshine...(o: - As well as helping you to get rid of excess fat and therefore lose excess fat, it also strengthens our bones and your muscles and helps you to avoid catching colds and flu.
If you cannot get out into the sun and need to take vitamin D supplements, Vitamin D3 are the best sort to get.
See vulnerable groups and fat retention