The Role of Fat-Soluble Vitamins
Fat-soluble vitamins differ from water-soluble vitamins. The fat-soluble are stored in body fat and require the presence of bile salts to be absorbed. Since they are stored in the body it is not absolutely necessary that you eat them every day. The fat-soluble vitamins are vitamins A, D, E, K and F.
The vitamin A complex is necessary for normal skin and mucous membrane function. It is required for such functions as the growth and formation of bones, muscle, cartilage and ligaments, immune system function, and the formation of tooth enamel. It also assists in pregnancy, fertility, adrenal function, thyroid function and normal eyesight. A study demonstrated that blood levels of vitamin A were low in 52 of 58 rheumatoid arthritis patients. Vitamin A reduces the risk of cancer development. It does so within its natural complex. Many of you may recall the increase in media attention concerning beta-carotene and cancer. Large doses of beta-carotene were thought to decrease incidence of cancer but a study of Finnish male smokers demonstrated otherwise. This was because they used a fraction of the vitamin A complex. Beta is just one of over six hundred carotenes!
Foods rich in vitamin A include egg yolks, butter, cheese, fish liver oils, sweet potato, carrots, spinach, butternut squash and dandelion greens.
Vitamin D is both a vitamin and a hormone. It is essential for healthy teeth and bones. Vitamin D helps maintain a healthy nervous system and muscle tone. We can get vitamin D through the diet or our bodies can produce vitamin D by exposure to sunlight. Since it is a fat-soluble vitamin it does require fat from food for absorption. Thus it is usually found in foods that contain fats. The elderly have a decreased ability to produce this vitamin. Vitamin D operates with the essential fatty acids to balance calcium and phosphorus bone ratios. It also helps to maintain normal blood calcium levels and may play a role in immune system function. Vitamin D can be stored in the liver, skin, brain and bones for future needs. Excessive consumption of the synthetic forms of the vitamin can result in calcium imbalance, calcium deposits in soft tissues and in an increase in lead absorption.
Foods that contain vitamin D include eggs, liver, cod liver oil, butter, fatty fish.
There is much yet to be learned about vitamin E. Our bodies contain a higher concentration of vitamin E than any other vitamin. It was given the name tocopherol which means to bring forth offspring although the vitamin E complex contains much more than tocopherol. Vitamin E is known as the anti-sterility vitamin. It is important for male and female reproduction, fertility and female uterine function. We also believe vitamin E complex functions to include protection from free radical damage, protection of red blood cells from damage, prevention of tumor growth, and the stabilization of cell membranes and tissues. It protects our genes and allows us to pass on hereditary characteristics. Vitamin E is required for hemoglobin production and strength of blood vessel walls. It works in conjunction with the trace element selenium. Studies demonstrate that low blood concentrations of vitamin E are more of a risk factor for the development of heart disease than high cholesterol or hypertension.
Foods rich in vitamin E include plant oils, leaves and other green portions of plants and wheat germ oil, egg yolk, butter, poppy and sesame seeds, barley, alfalfa, asparagus, prunes and sunflower seeds.
Vitamin K can be derived from plant, animal, as well as bacterial sources. It is involved in plant photosynthesis. Vitamin K is necessary for blood clotting. It helps to form the clot to stop the bleeding in case of a cut or other injury. Vitamin K has also been found to work with calcium and vitamin D. It is necessary for early bone development and the maintenance of healthy bones. There is a link between this vitamin and the development of osteoporosis. Vitamin K is a very important part of the vitamin C complex and assists vitamin C in various functions. The pair is usually found together in green plants. Substantial amounts of vitamin K may be lost due to antibiotic therapy. Those undergoing anticoagulant therapy and postmenopausal women demonstrate increased risk of vitamin K deficiency. Chlorophyll in plants is a great source of vitamin K. The water-soluble form of chlorophyll is the refined form and does not function as the fat-soluble (water-insoluble) natural form.
Foods rich in vitamin K include egg yolk, beef liver, whole wheat, alfalfa, spinach, broccoli, kale, brussels sprouts, cabbage, turnip greens and other green leafy vegetables. In smaller amounts, vitamin K is found in cereals, fruits, dairy products, and meats. We can also make some vitamin K in the gastrointestinal tract.
Be sure to include foods containing fat-soluble vitamins in your diet. Read here about fats in the diet.