What’s the need for fat-soluble vitamins?
Fat-soluble vitamins (vitamins A, D, E, and K) are a group of vitamins that have the ability to dissolve in the fats and oils in the body. They are mostly gotten from animal products, plants, as well as vitamin supplements.
Fat-soluble vitamins have a diversity of functions that range from strengthening the immune system to maintaining healthy bones and skin, vision, enabling blood clotting and so much more.
Every now and then, for a variety of reasons, some unknown to us, some of these vitamins can get depleted. A deficiency in any of these vitamins will cause problems in the body which will invariably manifest as a number potentially serious signs and symptoms including excessive internal or external bleeding, inability to walk, or in extreme cases, blindness.
Below are a few points about these important vitamins.
The main role of vitamin A in the body is to facilitate normal vision by producing the pigments of the retina in the eyes, as well as to support the bones, teeth, skin, and mucous membranes.
The best known dietary sources of vitamin A are beef, chicken, liver, fish, carrots, spinach, sweet potatoes and so much more. While it is advisable to ensure you eat foods that are rich in vitamin A, it is important to be cautious, as too much vitamin A can cause problems.
Vitamin A deficiency is particularly common in developing countries and can manifest as vision disturbances including blindness. As a matter of fact, vitamin A is actually a leading cause of blindness.
The principal roles of vitamin D in the body are to help the body absorb calcium in order to build and maintain strong bones, as well as to strengthen the immune system.
There are 3 key ways by which we get vitamin D- exposing the skin to sunlight (especially the UVB rays), taking vitamin supplements, and eating foods that contain vitamin D.
The most reliable dietary sources of vitamin D include fatty/oily fish (salmon, sardines, trout, mackerel), cod liver oil, and egg yolks. Seeing as vitamin D rich foods are mostly animals and animal products, strict vegans are at increased risk of vitamin D deficiency. There truly isn’t enough vitamin D in food to account for the amount of vitamin D the body needs, and so it’s important to ensure you get your additional vitamin D from other sources (sunlight and supplements).
Because it takes the skin being exposed to sunlight for the body to produce vitamin D, people that live further away from the equator, people with darker skin complexions, as well as people that spend most of their time indoors are more likely to develop vitamin D deficiency.
Some manifestations of vitamin D deficiency include fatigue, recurrent bacterial and viral infections, bone pain (especially back pain), decreased bone density (rickets in children, osteoporosis in adults), mood deterioration (particularly depression), slow wound healing, and muscle pain.
Its main roles are to strengthen the immune system, as well as act as an antioxidant by protecting the body’s cells and tissues from damage caused by harmful free radicals.
Vitamin E is widely available in most of the foods we eat daily, and so becoming deficient in vitamin E is uncommon. However, when it does occur, it is usually due to an underlying medical illness such as cystic fibrosis, cholestasis, Crohn’s disease, chronic pancreatitis, and primary biliary cirrhosis. Vitamin E deficiency can also occur as a result of genetics and in premature infants.
Vitamin E deficiency can present as muscle pain and weakness, numbness and tingling sensations in limbs, recurrent infections, problems with gait and coordination, problems with vision, and so on.
Vitamin K has 2 major forms- vitamin K1 (phylloquinone) and vitamin K2 (menaquinone). K1 is present in green leafy vegetables (especially kale and spinach), while K2 is produced naturally in the intestines.
Vitamin K’s main role is in blood clotting, which is necessary to prevent uncontrolled bleeding. It aids in the production of the proteins that facilitate blood clotting. Hence, a deficiency of vitamin K presents as excessive bleeding internally or externally.
Vitamin K deficiency is commonest in infants.
The main causes of vitamin K deficiency include taking certain medications such as warfarin (an anticoagulant or blood thinner) and antibiotics or having an underlying medical condition such as malabsorption which impairs the effective absorption of fat.
Featured image: Mr Vitamins
Dr. Wendy Evans-Uhegbu is a graduate of The Royal College of Surgeons in Ireland, with experience in Connected Health, Medical Technology, Clinical Research, Medical Education, and Web Design. She is a member of the Medics Abroad team with the role of Chief Communications Officer. She also runs a Medical Communications and Publishing business, and is the author of the newly published children’s book “The Things Around Me”.