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.
There are few natural food sources of vitamin D, although oily fish such as tuna or salmon are among the best. For example, 3 ounces of cooked salmon contains 447 IUs of vitamin D per serving. Small amounts are also found in cheese and egg yolks.