Dairy products, while high in calcium, are low in magnesium. Green vegetables are high in magnesium. 1  A Quick and Essential Guide to Choosing Nutrient-Dense Foods For good overall health and disease prevention, a diet including a large variety of nutrient-dense foods is critical.-2 cups or 5-6 ounces of these fish, with or without bones, are enough to provide up to 300 mg of calcium. You can also buy canned salmon and enjoy a healthy meal full of nutrients.   The last of our 3 food sources of calcium is calcium fortified orange juice.
Non-renewable energy resource: an energy resource that is not replaced or is replaced only very slowly by natural processes. Primary examples of non-renewable energy resources are the fossil fuels --oil, natural gas, and coal.
Renewable energy is the energy which is generated from natural sources i.e. sun, wind, rain, tides and can be generated again and again as and when required. They are available in plenty and by far most the cleanest sources of energy available on this planet. The non-renewable sources of energy that we are using are limited and are bound to expire one day. 2  Renewable sources have low carbon emissions, therefore they are considered as green and environment friendly. 3  Renewable helps in stimulating the economy and creating job opportunities.