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Home , Vitamin E, Vitamin E deficiency, Vitamin K

Fat-Soluble : A, D, E, and K Fact Sheet No. 9.315 Food and Series|Health by J. Clifford and A. Kozil* What are Vitamins? any potential health problems that may Quick Facts Vitamins are essential micronutrients interfere with absorption. • Small amounts of vitamin required by the body in small amounts A, , and to support a range of vital functions. : Vitamins are divided into two groups: are needed to -soluble (B-complex vitamins and C maintain good health. What is Vitamin A? vitamins) and -soluble vitamins (A, D, • Fat-soluble vitamins will not E and K). Unlike water-soluble vitamins Vitamin A, also called retinol, has be lost when the foods that that need regular replacement in the many functions in the body. In addition to contain them are cooked. body, fat-soluble vitamins are stored helping the eyes adjust to light changes, in the and fatty tissues, and are vitamin A plays an important role in • The body does not need eliminated much more slowly than water- growth, tooth development, reproduction, these vitamins every day and soluble vitamins. For more information cell division, gene expression, and stores them in the liver and on water-soluble vitamins, see fact sheet regulation of the immune system. The adipose (fat) when not 9.312 Water-Soluble Vitamins: Vitamin skin, eyes, and mucous membranes of the used. B-Complex and . mouth, nose, throat and lungs depend on vitamin A to remain moist. Vitamin A is also • Most people do not need an important that may play a vitamin supplements. What are Fat-Soluble Vitamins? role in the prevention of certain . The fat-soluble vitamins, A, D, E, and • Megadoses of vitamins A, D, K, are stored in the body for long periods E or K can be toxic and lead of time and generally pose a greater risk to health problems. for toxicity than water-soluble vitamins • Requirements for vitamins when consumed in excess. Eating a normal, well-balanced will not lead to toxicity may be expressed in different in otherwise healthy individuals. However, mathematical units. Close taking vitamin supplements that contain attention should be paid to megadoses of vitamins A, D, E and K may ensure that similar units are lead to toxicity. being compared. While diseases caused by a lack of fat-soluble vitamins are rare in the United States, symptoms of mild deficiency can Food Sources for Vitamin A develop without adequate amounts of Eating a wide variety of foods is the best vitamins in the diet. Additionally, some way to ensure that the body gets enough health problems, such as inflammatory vitamin A. The retinol, retinal, and retinoic bowel disease (IBD), chronic pancreatitis, acid forms of vitamin A are supplied and , may decrease the primarily by foods of animal origin such as absorption of fat, and in turn, decrease dairy products, and liver. Some foods the absorption of vitamins A, D, E and of plant origin contain the antioxidant, K. Consult a medical professional about beta-, which the body converts to vitamin A. Beta-carotene, comes from © Colorado State University fruits and , especially those that Extension. 3/02. Revised 9/17. *J. Clifford, Colorado State University Extension food are or dark green in color. Vitamin and nutrition specialist , A. Kozil, graduate student. extension.colostate.edu Original fact sheet revised by L. Bellows, Colorado State A sources also include , , University Extension food and nutrition specialist and winter squash, dark green leafy vegetables assistant professor; and R. Moore, graduate student. and , all of which are rich in beta- 11/2012 . Revised 9/17. carotene. How Much Vitamin A Do We Need? of a concern than deficiencies. The Food Sources for Vitamin D Tolerable Upper Intake Level (UL) for The recommendation for vitamin A The primary food sources of vitamin adults is 3,000 mcg RAE (Table 2). It intake is expressed as micrograms (mcg) D are and other dairy products would be difficult to reach this level of retinol activity equivalents (RAE). fortified with vitamin D. Vitamin D is consuming food alone, but some Retinol activity equivalents account for also found in oily fish (e.g., herring, supplements contain the fact that the body converts only and sardines) as well as in high doses of vitamin A. Retinol is a portion of beta-carotene to retinol. liver oil. In addition to the vitamin the form of vitamin A that causes the One RAE equals 1 mcg of retinol or 12 D provided by food, we obtain vitamin greatest concern for toxicity. If you take mcg of beta-carotene (Table 1). The D through our skin which produces a multivitamin, check the label to be Recommended Dietary Allowance (RDA) vitamin D in response to sunlight. for vitamin A is 900 mcg/ day for adult sure the majority of vitamin A provided is in the form of beta-carotene, which males and 700 mcg/day for adult females. How much Vitamin D Do We Need? Compared to vitamin A containing appears to be safe. Some medications The Recommended Dietary foods, it takes twice the amount of used to treat acne, psoriasis, and other Allowance (RDA) for vitamin D appears carotene rich foods to meet the body’s skin conditions contain compounds as micrograms (mcg) of vitamin A requirements, so one may need that mimic retinol in the body. Much (vitamin D3) (Table 1). From 12 to increase consumption of carotene like excessive intake of dietary retinol, months to age fifty, the RDA is set at containing plant foods to meet the RDA these medications have been shown 15 mcg. Twenty mcg of cholecalciferol for vitamin A. to negatively impact bone health and equals 800 International Units (IU), Studies indicate that vitamin A result in delayed growth in children which is the recommendation for requirements may be increased due to and teens. maintenance of healthy bone for hyperthyroidism, fever, infection, cold, Symptoms of vitamin A toxicity adults over fifty. Table 1 lists additional and exposure to excessive amounts of include dry, itchy skin, headache, recommendations for various life sunlight. Those who consume excess nausea, and loss of appetite. Signs of stages. or have renal disease should also severe overuse over a short period of Exposure to ultraviolet light is increase intake of vitamin A. time include dizziness, blurred vision and slowed growth. Vitamin A toxicity necessary for the body to produce the active form of vitamin D. Ten to fifteen can also cause severe birth defects and may increase the risk for bone minutes of sunlight without sunscreen Vitamin A deficiency in the United loss and hip fractures. on the hands, arms and face, twice a States is rare, but the disease that week is sufficient to receive enough results is known as xerophthalmia, vitamin D. This can easily be obtained which can lead to blindness if Vitamin D in the time spent riding a bike to work untreated. It most commonly occurs or taking a short walk with arms and in developing nations usually due to What is Vitamin D? legs exposed. In order to reduce the . Since vitamin A is stored Vitamin D plays a critical role risk for skin one should apply in the liver, it may take up to 2 years sunscreen with an SPF of 15 or more, for signs of deficiency to appear. Night in the body’s use of and phosphorous. It works by increasing if time in the sun exceeds 10 to 15 blindness and very dry, rough skin minutes. may indicate a lack of vitamin A. Other the amount of calcium absorbed from the , helping to form and signs of possible vitamin A deficiency include decreased resistance to maintain . Vitamin D benefits the Symptoms of vitamin D deficiency infections, faulty tooth development, body by playing a role in immunity and in growing children include and slower bone growth. Vitamin A controlling and may protect (long, soft bowed legs) and flattening deficiency is also a known risk factor against , high of the back of the skull. Vitamin D for severe measles. According to the pressure, cancer, and other diseases. deficiency in adults may result in World Health Organization (WHO), Children especially need adequate (muscle and bone Vitamin A supplementation can amounts of vitamin D to develop weakness), and osteoporosis (loss significantly reduce mortality rates for strong bones and healthy teeth. of bone mass). Vitamin D deficiency children with measles who live in areas has been associated with increased with a high prevalence of Vitamin A risk of common cancers, autoimmune deficiency. The effectiveness of vitamin diseases, hypertension, and infectious A supplementation to treat measles in disease.Research shows that vitamin countries, such as the United States, D insufficiency affects almost 50% where vitamin A intakes are generally of the population worldwide; an adequate, is uncertain. estimated 1 billion people. The rising rate of deficiency has been linked to Too much Vitamin A a reduction in outdoor activity and In the United States, toxic or an increase in the use of sunscreen excess levels of vitamin A are more among children and adults. In addition, those who live in inner cities, wear grains, nuts ( and ), clothing that covers most of the skin, seeds (sunflower) and fortified cereals. or live in northern climates where little sun is seen in the winter are also prone How much Vitamin E Do We Need? to vitamin D deficiency. Since most The Recommended Dietary foods have very low vitamin D levels Allowance (RDA) for vitamin E is based (unless they are enriched) a deficiency on the most active and usable form may be more likely to develop without called alpha- (Table 1). adequate exposure to sunlight. Adding Food and supplement labels list alpha- fortified foods to the diet such as milk, large amounts of fortified foods may tocopherol as the unit international and for adults including a supplement, units (IU) or micrograms (mcg), not are effective at ensuring adequate cause accumulations in the liver and produce signs of poisoning. Signs in milligrams (mg). One microgram vitamin D intake and preventing low of alpha-tocopherol equals to 1.5 vitamin D levels. In the absence of of include excess calcium in the blood, slowed mental International units (IU). RDA guidelines adequate sun exposure, at least 800 to state that males and females over 1,000 IU of vitamin D3 may be needed and physical growth, decreased appetite, nausea and vomiting. the age of 14 should receive 15 mcg to reach the circulating level required (22.5 IUs) of alpha-tocopherol per day. to maximize vitamin D’s benefits. It is especially important that infants and young children do not consume Consuming vitamin E in excess of the RDA does not result in any added Who is at Risk — excess amounts of vitamin D regularly, due to their small body size. benefits. These populations may require extra vitamin D in the form of supplements or fortified foods: Vitamin E: Tocopherol Vitamin E deficiency is rare. Cases • Exclusively breast-fed infants: Human of vitamin E deficiency usually only milk only provides 25 IU of vitamin D per What is Vitamin E? occur in premature infants and in those liter. All breast-fed and partially breast- Vitamin E benefits the body unable to absorb . Since fed infants should be given a vitamin D by acting as an antioxidant, and oils are good sources of vitamin E, supplement of 400 IU/day. protecting vitamins A and C, red people who excessively reduce their blood cells, and essential fatty acids dietary fat may not get enough • Dark Skin: Those with dark pigmented from destruction. Research from vitamin E. skin synthesize less vitamin D upon decades ago suggested that taking exposure to sunlight compared to those antioxidant supplements, vitamin Too much Vitamin E with light pigmented skin. E in particular, might help prevent The Tolerable Upper Intake Level • Elderly: This population has a reduced heart disease and cancer. However, (UL) for vitamin E is shown in Table newer findings indicate that people 2. Vitamin E obtained from food ability to synthesize vitamin D upon who take antioxidant and vitamin E usually does not pose a risk for exposure to sunlight, and is also supplements are not better protected toxicity. Supplemental vitamin E is not more likely to stay indoors and wear against heart disease and cancer than recommended due to lack of evidence sunscreen which blocks vitamin D non-supplement users. Many studies supporting any added health benefits. synthesis. show a link between regularly eating Megadoses of supplemental vitamin • Covered and protected skin: Those an antioxidant rich diet full of fruits E may pose a hazard to people taking and vegetables, and a lower risk for blood-thinning medications such as that cover all of their skin with clothing heart disease, cancer, Alzheimer’s Coumadin (also known as ) while outside, and those that wear Disease, and several other diseases. and those on statin drugs. sunscreen with an SPF factor of 8, block Essentially, research indicates that to most of the synthesis of vitamin D from receive the full benefits of sunlight. Vitamin K • and phytonutrients in the diet, one Disease: Fat syndromes, should consume these compounds in inflammatory bowel disease (IBD), and the form of fruits, vegetables, nuts, and What is Vitamin K? obesity are all known to result in a seeds, not as supplements. Vitamin K is naturally produced decreased ability to absorb and/or use by the in the intestines, and Food Sources for Vitamin E vitamin D in fat stores. plays an essential role in normal blood About 60 percent of vitamin E in clotting, promoting bone health, and Too much Vitamin D the diet comes from vegetable oil helping to produce for blood, The Tolerable Upper Intake Level (, corn, cottonseed, and bones, and kidneys. (UL) for vitamin D is set at 100 mcg ). This also includes products (4000 IUs) for people 9 years of age made with vegetable oil ( Food Sources for Vitamin K and older (Table 2). High doses of and salad dressing). Vitamin E sources Good food sources of vitamin K are vitamin D supplements coupled with also include fruits and vegetables, green, leafy-vegetables such as Table 1. Recommended Dietary Intake (RDA) and Adequate Intake (AI) for Fat-Soluble Vitamins

Life Stage Group Vitamin A Vitamin D Vitamin E Vitamin K (mcg1/RAE) (mcg2) (mcg a-TE3) (mcg) Infants4 0 - 6mo 400* 10* 4* 2.0* 6mo - 12mo 500* 10* 5* 2.5* Children 1 - 3y 300 15 6 30* 4 - 8y 400 15 7 55* Males 9 - 13y 600 15 11 60* 14 - 18y 900 15 15 75* 19 - 30y 900 15 15 120* 31 - 50y 900 15 15 120* 51 - 70y 900 15 15 120* >70y 900 20 15 120* Females 9 - 13y 600 15 11 60* 14 - 18y 700 15 15 75* 19 - 30y 700 15 15 90* 31 - 50y 700 15 15 90* 51 - 70y 700 15 15 90* >70y 700 20 15 90* Pregnant 14 - 18y 750 15 15 75 19 - 30y 770 15 15 90 31 - 50y 770 15 15 90 Lactation 14 - 18y 1200 15 19 75 19 - 30y 1300 15 19 90 31 - 50y 1300 15 19 90

1As retinol activity equivalents (RAEs). 1 RAE = 1mcg retinol or 12 mcg beta-carotene. 2As cholecalciferol (vitamin D3). 10 mcg cholecalciferol = 400 IU of Vitamin D. 3As alpha-tocopherol equivalents. 1 mg of alpha-tocopherol = 1.5 IU of Vitamin E=22IU of d-alpha-tocopherol=33 IU of dl-alpha- tocopherol

4At 6 months of age, infants may be introduced to solid foods while remaining on formula or . There may be some overlap in specific requirements. *Indicates an Adequate Intake (AI). All other values are Recommended Dietary Allowance (RDA). Table 2. Tolerable Upper Intake Levels (UL) for Fat-Soluble Vitamins

Life Stage Group Vitamin A Vitamin D Vitamin E Vitamin K* (mcg/d) (mcg/d) (mg a-TE) Infants1 0 - 6mo 600 25 ND2 ND 6mo - 12mo 600 38 ND ND Children 1 - 3y 600 63 200 ND 4 - 8y 900 75 300 ND Males/Females 9 - 13y 1700 100 600 ND 14 - 18y 2800 100 800 ND 19 - 70y 3000 100 1000 ND >70y 3000 100 1000 ND Pregnant and Lactating <18 2800 100 800 ND 19 - 50y 3000 100 1000 ND

1At 6 months of age, infants may be introduced to solid foods while remaining on formula or breast milk. There may be some overlap in specific nutrient requirements.

2ND = not determinable due to insufficient data *An UL for vitamin K was not established. greens, , , and , and certain vegetables oils including , cottonseed Summary oil, and oil. Animal foods, in general, contain limited • Fat-soluble vitamins: A, D, E, and K — amounts of vitamin K. are stored in the body for long periods of time, and pose a greater risk for toxicity How Much Vitamin K Do We Need? than water-soluble vitamins. Fat-soluble To help ensure people receive vitamins are only needed in small sufficient amounts of vitamin K, amounts. an Adequate Intake (AI) has been established for each age group (Table • Beta carotene is an important antioxidant 1). that the body converts to Vitamin A, with chronic diarrhea may have and it is found in a variety of fruits and problems absorbing sufficient amounts vegetables. Without sufficient amounts of of vitamin K through the intestine • Inadequate dietary consumption vitamin K, hemorrhaging can occur. and should consult their physician of vitamin D, along with limited sun to determine if supplementation is Vitamin K deficiency may appear exposure, makes vitamin D deficiency a in infants or in people who take necessary. growing public health concern. , such as Coumadin (warfarin), or antibiotic drugs. Too much Vitamin K • Vitamin E benefits the body by acting as Newborn babies lack the intestinal Although no Tolerable Upper Intake an antioxidant, and research indicates bacteria to produce vitamin K and Level (UL) has been established for that it may offer a protective effect if need a supplement for the first week. vitamin K, excessive amounts can obtained through a diet rich in fruits and Those on drugs (blood cause the breakdown of red blood vegetables, as opposed to a supplement thinners) may become vitamin K cells and liver damage. People taking or multivitamin. deficient, but should not change their blood-thinning drugs or anticoagulants vitamin K intake without consulting a should moderate their intake of foods • The bacteria in our gut produce vitamin physician. People taking antibiotics with vitamin K, because excess vitamin K, and it is also found in green leafy may lack vitamin K temporarily K can alter blood clotting times. Large vegetables. because intestinal bacteria are doses of vitamin K are not advised. sometimes killed as a result of long- term use of antibiotics. Also, people References Berdanier, C., Berdanier, L., Zempleni, J. (2009). Advanced Nutrition: Macronutrients, Micronutrients, and . Boca Raton, FL: CRC Press, Taylor & Francis Group.

Duyff, R. (2012). American Dietetic Association: Complete Food and Nutrition Guide. Hoboken, NJ: John Wiley & Sons, Inc.

Gropper, S., Smith, J. (2009).Advanced Nutrition and Human Metabolism. Belmont, CA: Wadsworth, Cengage Learning.

Holick, M., Chen, T. (2008). Vitamin D deficiency: a worldwide problem with health consequences. American Journal of Clinical Nutrition, 87 (4), 1080-1086.

Institute of Medicine (US). (2002). Dietary Reference Intakes for Vitamin A, Vitamin K, Arsenic, Boron, Chromium, Copper, Iodine, Iron, Manganese, , Nickel, Silicon, Vanadium, and Zinc. Washington, DC: National Academy Press.

Institute of Medicine (US). (2000). Dietary Reference Intakes for Vitamin C, Vitamin E, , and . Washington, DC: National Academy Press.

Institute of Medicine (US) Committee to Review Dietary Reference Intakes for Vitamin D and Calcium; Ross A., Taylor, C., Yaktine, A., et al., editors. (2011). Dietary Reference Intakes for Calcium and Vitamin D. Washington, DC: National Academies Press. Retrieved from: https://www.ncbi. nlm.nih.gov/books/NBK56070/ doi: 10.17226/13050.

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