Cardiac muscle (heart muscle). This type of muscle is found solely in the walls of the heart. It has similarities with skeletal muscles in that it is striated and with smooth muscles in that its contractions are not under conscious control. However this type of muscle is highly specialised.t has similarities with skeletal muscles in that it is striated and with smooth muscles in that its contractions are not under conscious control. However this type of muscle is highly specialised.
There are few natural sources of vitamin D. For that reason, most of the vitamin D in your diet comes from fortified foods, such as dairy products and alternatives, breakfast cereals, juices and margarine.
Vitamin D comes from two places - we take it into our bodies in foods and supplements, and our bodies produce it after sunlight exposure. Vitamin D is found naturally in only a few foods like fatty fish (for example, cod liver oil) and egg yolks. Because there are so few natural dietary sources, vitamin D is added to foods such as fortified soymilk, fortified juice, fortified breakfast cereals, cow's milk, and margarine.