Vitamin D: The essential fat-soluble vitamin
Vitamin D | What is vitamin D? | What does vitamin D do in your body?
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Vitamin D is a fat-soluble vitamin that is naturally present in some foods, added to other foods, and available as a dietary supplement. Vitamin D is also produced endogenously when ultraviolet rays from sunlight strike the skin and then trigger vitamin D synthesis.
Vitamin D is an essential nutrient required for bone health.
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Vitamin D helps the body absorb calcium; Vitamin D helps deposit calcium and phosphorus in bones and teeth and makes them strong. Calcium is one of the primary building materials for strong bones. Bones are living tissues, and they are constantly being remodeled. Vitamin D, together with calcium, helps protect from developing osteoporosis.
Healthy bones support the surrounding muscles to assist with balance and postural sway, reducing the risk of falling. Vitamin D is also needed for muscle fibers' normal development and growth.
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Vitamin D is an essenital nutrient for health
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Vitamin D is needed for nerves to carry messages between the brain and body and for muscles to move.
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Vitamin D is required for your immune system to fight off invading bacteria and viruses.
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Vitamin D helps regulate cell growth and neuromuscular function.
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Vitamin D helps the body regulate blood sugar levels. Vitamin D plays a vital role in glucose metabolism. In addition, vitamin D stimulates insulin secretion and decreases peripheral insulin resistance through vitamin D receptors in muscles and the liver.
The nutritional food sources of vitamin D
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Very few natural foods have Vitamin D. Vitamin D-fortified foods provide most of the vitamin D in people's diets in the U.S. and Canada. Check the nutrition facts label for vitamin D in a food or beverage. Almost all U.S. milk supply is fortified with about three micrograms of vitamin D per cup. In addition, many plant-based alternatives, such as oat milk, soymilk, and almond milk, are similarly fortified.
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Vitamin D is added to many breakfast cereals and some brands of orange juice, yogurt, and other food products. You need to check the product label for nutrition facts.
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Fish liver oils and fatty fish like trout, salmon, mackerel, and tuna are among the best natural food sources of vitamin D.
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Egg yolks and beef liver has small amounts of vitamin D. Mushrooms provide a little vitamin D.
The top foods of good sources of vitamin D
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Cod liver oil
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Trout
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Salmon
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Milk, vitamin D fortified
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Breakfast cereals, vitamin D fortified
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Soy milk, almond milk, and oat milk, vitamin D fortified
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Sardine
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Eggs
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Beef liver
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Tuna
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Cheese, cheddar
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Mushrooms
Recommended Amounts: How much vitamin D do we need?
For people 14 to 70 years old, the RDA is 15 micrograms daily, and for adults 71 years and older, the RDA is 20 micrograms daily.
For pregnant and breastfeeding teens and women (14 to 50 years old females in pregnancy and lactation), the RDA is 15 micrograms daily.
Getting too much vitamin D can be harmful. Excess amounts of vitamin D are toxic. The daily upper limits (UL) for vitamin D include intake from all sources-foods, beverages, and supplements, is 100 micrograms for people 14 years and older, including pregnant and breastfeeding teens and women (14 to 50 years old females in pregnancy and lactation).
However, UL levels do not apply to people taking vitamin D for medical reasons under a doctor's care.
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The daily upper limits for vitamin D include intakes from all sources—food, beverages, and supplements—and are listed below in micrograms (mcg) and international units (IU). However, your health care provider might recommend doses above these upper limits for a period of time to treat a vitamin D deficiency.
RDAs for vitamin D are lsited in both micrograms (mcg) and international units (IU). One microgram (mcg) vitamin D is euqal to 40 IU (international units).For infants, AIs are listed in the table.
Recommended Dietary Allowance (RDA):
What is RDA? RDA means Recommended Dietary Allowances; RDA is the daily nutritional sufficient nutrient level. RDA is the dietary intake value that represents what you need to take on a daily basis. RDA is the average daily level of intake sufficient to meet the nutrient requirements of nearly all (97%-98%) healthy individuals.
Vitamin D and Healthful Diets
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Our nutritional needs should be met primarily through foods because foods provide an array of nutrients and other components that benefit health. Foods contain vitamins, minerals, dietary fiber, and other nutrients that are beneficial for our health. In some situations and cases, fortified foods and dietary supplements are helpful when it is impossible to meet the needs for one or more nutrients.
A healthy dietary pattern was described by “The Dietary Guidelines for Americans” as one that:
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Includes a variety of vegetables; fruits; grains, and whole grains; milk, yogurt, cheese; and oils. Many ready-to-eat cereals, milk and yogurt of some brands, and orange juice are fortified with vitamin D; you need to check the nutrition fact label of the product. Cheese naturally has small amounts of vitamin D. Vitamin D is added to some margarine.
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Includes a variety of protein foods, for example, meats, poultry, eggs, seafood, beans, peas, lentils, nuts and seeds, and soy products. Fatty fish, including salmon, tuna, and mackerel, are excellent nutritional sources of vitamin D. Egg yolks and beef liver have small amounts of vitamin D.
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Limits foods and beverages higher in sodium, added sugar, and saturated fat.
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Limits alcoholic beverages.
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Stays within your daily calorie needs.
References:
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Institute of Medicine, Food and Nutrition Board. Dietary Reference Intakes for Calcium and Vitamin D. Washington, DC: National Academy Press, 2010.
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https://ods.od.nih.gov/factsheets/VitaminD-HealthProfessional/, updated August 12, 2022
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