Calcium – is vital for strong bones and healthy teeth. Lack of calcium can lead to osteoporosis so people with a family history of the disease or those who have been on steroids for a long time can reduce their risk by ensuring they eat enough calcium rich foods. Calcium works best combined with vitamin D and magnesium.
Easy ways to get enough are to have 2-3 servings of dairy a day, like plenty of milk on your cereal, a yoghurt and a matchbox sized piece of cheese. Lower fat dairy products are better – semi-skimmed milk is both richer in calcium and lower in saturated fat. There are quite a few studies showing that low fat dairy products can aid weight loss – although quite why has not be established. Other good sources of calcium are sardines, tofu, leafy greens (like kale and watercress), pulses, sesame seeds and fortified soya milk.Taking weight bearing exercise, like walking, can help maintain bone mass. Making sure you get your essential fatty acids (oily fish, nuts etc) can also help ensure you absorb the calcium in your diet.
If you want to find out more, I recommend starting here at the US National Institutes of Health factsheet.