Fat Soluble Vitamins

1. Fat Soluble Vitamins Fat soluble vitamins A,D,E,and K quite different from the water-soluble vitamins in many ways. Because they are insoluble in water, the fat soluble vitamins need bile to interact with for their absorption. Once absorbed, fat-soluble vitamins must travel through the lymphatic system using special carriers called chyomicrons. After processing in the liver, fats entering the bloodstream requires protein carriers for transport through the bloodstream. “Lecture 10: Fat Soluble Vitamins PowerPoint" by Dr. Michael Kobre, Achieving the Dream OER Degree Initiative, Tompkins Cortland Community College is licensed under CC BY 4.0

2. The Fat Soluble Vitamins • Fat-soluble vitamins participate in many different activities in the body. Unlike the water soluble vitamins, fat soluble vitamin excesses are stored primarily in the liver and adipose tissue. Our body maintains blood normal blood concentrations of fat soluble vitamins by retrieving these vitamins from storage as needed. Because of this, people can eat less than their daily needs for even, months or years without deficiency issues.

3. The Fat Soluble Vitamins In most cases we need only to ensure that our average daily intakes equal approximate recommendations. Because fat-soluble vitamins are not readily excreted like water soluble vitamins are, the risk of toxicity is higher for fat soluble vitamins than it is for the water-soluble vitamins.

4. Vitamin A and Beta-Carotene • Vitamin A was the first fat-soluble vitamin to be discovered and researched. Almost a 100 years later, vitamin A and its precursor, beta-carotene, continue to amaze researchers with their diverse roles in the body and effects on our health.

5. Vitamin A and Beta-Carotene There are three different forms of vitamin A that are active in the body: retinol, retinal, and retinoic acid. These three compounds are known as retinoids. Foods that come from animal products provide compounds that are easily converted to retinol in the intestine. Foods from some plants provide carotenoids, which have vitamin A activity.

6. Vitamin A Roles in the Body Vitamin A is a versatile vitamin. Its major roles include: Roles in vision Participating in protein synthesis and cell differentiation. Reproduction and growth roles.

7. Vitamin A Roles in the Body Vitamin A plays two important roles in vision: It helps maintain a crystal-clear cornea, and it participates in chemical conversion of light energy into nerve impulses in the retina. Visual activity causes continuous small losses of retinal and thus requires a constant replenishment from retinol in the blood stream. Replacement retinol comes from stored retinol in adipose tissue and from the liver.

8. Vitamin A Roles in the Body In the cells that line the body surface and organs inside of our body, vitamin A participates in protein production and cell differentiation. Vitamin A helps promote cell differentiation of both epithelial cells that line organs and goblets cells that produce mucus.

9. Vitamin A Roles in the Body Vitamin A also has roles in both reproduction and growth. In males, retinol participates in sperm development. In women, it helps to support normal fetus development during pregnancy.

10. Vitamin A Deficiency • Vitamin A status in the body depends mainly on the vitamin A stored in the body. Approximately 90% of stores are in our liver. Vitamin A status also depends on a person’s protein status because retinol-binding protein needs to be present as the vitamin’s transport carrier inside the body. If a person were to stop eating vitamin A rich foods, deficiency symptoms would not develop for quite some time, one to two years in most healthy adults . Growing children would become deficient sooner because they demand more for their faster growth.

11. Vitamin A Deficiency People are more at risk for infectious diseases when they are deficient in vitamin A. • Night Blindness: is one of the 1st detectable signs of vitamin A deficiency in humans. • Blindness (Xerophthalmia): if a vitamin A deficiency goes untreated, total irreversible blindness can occur. This condition is rare in developed countries but does occur in poor, under-developed areas globally.

12. Vitamin A Deficiency • Keratinization: A condition of dry, rough, scaly skin. This condition can weaken the body’s protective outer skin. It can inhibit respiratory functions, gastrointestinal functions, and immune system defenses.

13. Vitamin A Toxicity • Just as a deficiency of vitamin A can affect all body systems, so can a toxic levels of vitamin A. Most all symptoms of a toxicity of vitamin A start to develop when all the binding proteins for vitamin A become overwhelmed and free vitamin A starts to damage the body’s cells. Beta-carotene, which is found in a wide variety of fruits and vegetables is not converted efficiently enough in the body to reach toxic levels. Overconsumption of beta-carotene from foods can turn the skin a yellowish color, but this is not harmful.

14. Vitamin A Toxicity Be forewarned that an overconsumption of beta-carotene from vitamin supplements can reach toxic levels and may become detrimental to the body. When taken in excess vitamin A and activated beta-carotene from supplements may act as a prooxidant, promoting excessive cell division and other physiological issues.

15. Vitamin A Toxicity • Birth defects: excessive intakes of vitamin can cause a teratogenic risk. Past research as shown that women who took more than 10,000 IU of supplemental vitamin A daily that increased risks of developing fetal growth issues. Roughly one out of every fifty seven infants was born with a malformation that was attributable to vitamin A toxicity. High intakes before the 7th week of fetal development appear to be the most damaging. Vitamin A should not be consumed during the 1st trimester of pregnancy unless there is evidence of a clinical deficiency, which is quite rare.

16. Vitamin A Recommendations • Because the body can convert vitamin A from various retinoids and cartenoids, contents in foods and recommendations are expressed as retinol activity equivalents (RAE) • Men: 900 µg RAE/day • Women: 700 µg RAE/day • Upper level: 3000 µg RAE/day

17. Vitamin A Food Sources • Retinol: found in: fortified milk, cheese, cream, butter, eggs, liver. • Beta-cearotne found in: Dark leafy greens, broccoli, deep orange fruits and vegetables.

18. Vitamin D • Vitamin D (calciferol) is different from all the other fat-soluble vitamins in that our body can synthesize it. With the energy of sunlight, and a molecule that the body makes from cholesterol, we can make vitamin D. Because of this, vitamin D is not considered an essential nutrient. If we spend some time in the sun and have normal health, we can survive with no vitamin D from foods we consume.

19. Vitamin D Regardless of whether the body makes Vitamin D3 or we consume it in foods, two reactions must occur before the vitamin becomes fully active and available for use. First, our liver performs a chemical reaction that adds an OH group, then our kidneys adds another OH group that actives the vitamin. liver and or kidney dysfunctions can interfere with activation of vitamin D and can cause a deficiency.

20. Vitamin D In The Body Vitamin D is actually a hormone. Bone Growth: Vitamin D is a member of a large bone synthesizing and maintenance team. Vitamin D’s function is to maintain blood concentrations of calcium and phosphorus in the body. Vitamin D raises blood concentrations of minerals in three ways. It enhances mineral absorption in the GI tract, mineral reabsorption by the kidneys, and mineral mobilization from the bones into the blood.

21. Vitamin D Roles In The Body Through research scientists have indentified many other vitamin D target tissues in the body; the brain and nervous system, pancreas, skin, muscles and cartilage, reproductive organs, and even in cancer cells. These findings suggest that vitamin D has numerous functions and may be valuable in treating a number of functional disorders, including treating cancer.

22. Vitamin D Deficiency Rickets: Is a condition that affects many children globally. Rickets causes failure of the bones to calcify normally leading to bone growth retardation and skeletal abnormalities. The bones become so weak with this condition that they bend when they support the body’s weight. A child with rickets characteristically develops bowed leg bones and arms bones.

23. Vitamin D Deficiency Issues • Osteomalacia: Is the adult form of rickets… • Osteoporosis: Is a loss of calcium from the bones (decreased bone density), which can result in fractures. This is more common in women and in men. • The elderly: because of lowered liver and kidney functions as we age, we can develop vitamin D deficiencies.

24. Vitamin D Toxicity Consuming an excess of vitamin D raises our concentration of blood calcium. Excessive blood calcium levels tend to precipitate out of blood and deposit into soft tissues of the body. The deposition can cause calcifications such as stones, especially in the kidneys and gall bladder. Calcification may also harden the blood vessels, where it may cause cardiovascular insult and premature death.

25. Vitamin D Sources • Most adults, especially in sunny areas, need not make special efforts to obtain D from food. Children who use sun screen and elderly folks that stay inside out the of sun may require additional supplementation. • Food sources: fortified dairy products, cereals, veal, beef, eggs, and fatty fish.

26. Vitamin E Vitamin E is a fat-soluble vitamin with antioxidant properties and is one of the body’s primary defenders against the adverse effects of free radical damage, Vitamin E functions to inhibit free radical reactions from producing more even more free radicals. In doing so, vitamin E protects the vulnerable components of the cells and their membranes from destruction by being sacrificially destroyed itself sparing our cell’s components.

27. Vitamin E Research suggests that vitamin E may help reduce the risk of heart disease by protecting protein transporters from dysfunctional oxidation.

28. Vitamin E Deficiency Issues • Erythrocyte hemolysis: A condition sometimes seen in premature infants, born before the transfer of Vitamin E from the mother to the infant that takes place during the last weeks of a normal pregnancy. • Prolonged vitamin E deficiency may also induce neuromuscular dysfunctions involving the spinal cord and the retina of the eye. Leg cramps (intermittent claudication), weakness, and difficulty walking are also symptoms that can occur.

29. Vitamin E Toxicity • Toxicity of vitamin E is fairly rare. Extremely high doses may sometimes interfere with the blood-clotting function of vitamin K and can enhance the effects of drugs used by folks to oppose blood clotting, causing hemorrhage. People on blood thinning medication as an example may develop uncontrolled bleeding.

30. Vitamin E recommendations • 2000 RDA: • Adults: 15 mg/day • Upper level: 1000 mg/day • Food sources: dark green leafy vegetables, wheat germ, nuts, seeds, egg yolks, whole grains, liver, plant oils.

31. Vitamin K • Vitamin K is essential for the activation of several of the molecules that function in the blood-clotting cascade, the physiological process that stops bleeding. • Vitamin K is also involved in the synthesis of bone proteins. Without vitamin K, the bones will produce an abnormal protein that cannot bind the minerals that normally form our bones. This can lead to bone density issues.

32. Vitamin K Deficiency Uncontrolled Hemorrhaging. Bone density issues and skeletal weakness.

33. Vitamin K Toxicity • Toxicity with vitamin K is uncommon but may result when vitamin K supplements are prescribed and consumed, especially to infants and pregnant women. • Toxicity symptoms can include red blood hemolysis, jaundice, and brain damage. • Also people taking anticoagulant medications to thin their blood should be careful with vitamin K intake.

34. Vitamin K Recommendations and Sources • 2001 AI: • Men: 120 µg/day • Women: 90 µg/day • Sources: Bacteria in the GI tract produce vitamin K that we can absorb and utilize. Foods such as liver, dark green leafy vegetables, milk, cabbage type vegetables are good sources.