Fat Soluble Vitamins E, A, K and D
- ciaralitchfield
- Oct 22, 2014
- 3 min read
Vitamins and Minerals
These micronutrients are needed in small amount per day. They allow the body to produce vital enzymes, hormones and other substances needed for normal growth and development. Deficiencies in Iodine, Vitamin A and Iron are global public health concerns. Deficiencies pose a major threat to the health and development of populations, particularly children, the elderly, pregnant women and those in low income countries.
There are 2 types of Vitamins: Water soluble and fat soluble, this post will cover fat soluble vitamins E, A, K and D
Vitamin E
Vitamin E includes a family of 8 antioxidants that protect lipids and other vulnerable components of cells from destruction. They are also involved in the protection of metabolic equipment stored in the mitochondria. Vitamin E helps the lungs to combat air pollutants by protecting blood cells and lung tissue from the pollutants in the lung cavities. This protecting means white blood cells immune function is supported keeping our defences high.
Fat mal-absorption is the disease associated with Vitamin E deficiency and leads to loss of muscle mass and reduced functioning due to overall weakness. Luckily deficiency in humans is very rare. Vitamin E sources include Vegetable oils, leafy vegetables, whole grain and wheat germ. Ani8mal fats contain little to no vitamin E. You should be getting around 13.4 mg a day if you’re male and 15mg a day if you’re female.
For Vitamin E to become toxic you would need in excess of 1200mg a day which would lead to extreme haemorrhaging and nausea. It’s very unlikely as the vitamin is well tolerated by humans
Vitamin A
Vitamin A promotes vision by aiding our bodies to maintain a clear cornea. Vitamin A supports the conversion of light into nerve impulses which reach the retina via photo-receptors. Vitamin A activates this process, if stores are running low we may experience night blindness as its harder to process the low levels of light available, further depleting our stores. A larger amount of Vitamin A is stored in epithelial cells in the skin and muscles. The vitamin maintains healthy cells aiding immunity as bacterial invasion is prevented by the barrier of healthy cells.
Deficiency can cause blindness as visual pigments are not regenerated, night blindness is the first state and can be treated. There is also an effect on goblet cells present in the stomach and intestine. The reduced number of cells means absorption and digestion of nutrients is impaired. The skin will become dry and scaly lumps may appear. Vitamin A can be found in liver, fish and dairy foods, its precursor is present in red, yellow and orange foods and will be converted to retinol in the body.
Adults should consume between 600-700 μg a day. Excess is unlikely and may lead to damaged cells and a yellowing of the skin.
Vitamin K
Around 13 different proteins and calcium are involved in the blood clotting process; at least 4 of these require vitamin K for synthesis. Vitamin K synthesises the change from precursor to Prothrombin which begins the chain of event s leading to creation of Fibrin which forms a solid clot. Vitamin K is also involved in bone health and has been positively associated with a reduction in fracture rate and improved calcium balance.
Vitamin K sources include most green vegetables such as spring onions, Brussels sprouts, herbs, Broccoli and Asparagus. Safe intake is around 70 μg a day and deficiency, while rare, is very dangerous leading to impaired clotting resulting in uncontrollable bleeding.
Vitamin D
The fundamental difference between Vitamin D and other Vitamins is that the body can synthesise it, with the help of sunlight, from a precursor that the body makes from cholesterol. It occurs in only a few common foods mainly fish oils, livers, eggs and milk. Outside of the diet 10-15 minutes of exposure to UV light should be adequate to receive enough Vitamin D. This can be on your face, hands, arms or anywhere else so sunbathing isn’t necessary.
Vitamin D is essential as it aids absorption of Calcium from the small intestine. This is important for formation and maintenance of bone health. Vitamin D deficiency causes a condition named Rickets so getting enough is especially important for children.
