Vitamin A 10 000 Iu Benefits

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Vitamin A 10 000 Iu Benefits

Vitamin A is a fat-soluble vitamin that helps maintain healthy vision, growth and development in children, as well as immune function. It’s also needed for the body to make use of other vitamins such as K and E.

Vitamin A helps protect against infection by boosting immunity and helping the body fight off bacteria and viruses. It also supports healthy skin, hair and nails by maintaining their integrity.

The recommended daily allowance (RDA) for vitamin A is 900 micrograms (mcg) for men and 700 mcg for women, according to Health Canada’s Food Guide.

Vitamin A 10 000 Iu Benefits

Vitamin A is a fat-soluble nutrient that plays a vital role in your body.

It exists naturally in foods and can also be consumed through supplements.

This article discusses vitamin A, including its benefits, food sources of the vitamin, and the effects of deficiency and toxicity.

Tim Macpherson/Getty Images
What is vitamin A?
Though vitamin A is often considered a singular nutrient, it’s really a group of fat-soluble compounds, including retinol, retinal, and retinyl esters (1Trusted Source, 2Trusted Source).

Two forms of vitamin A are found in food.

Preformed vitamin A — retinol and retinyl esters — occurs exclusively in animal products such as dairy, liver, and fish, while provitamin A carotenoids are abundant in plant foods like fruits, vegetables, and oils (3Trusted Source).

To use both of these forms of vitamin A, your body must convert them to retinal and retinoic acid, the active forms of the vitamin.

Because vitamin A is fat-soluble, it’s stored in body tissue for later use.

Most of the vitamin A in your body is kept in your liver in the form of retinyl esters (4Trusted Source).

These esters are then broken down into all-trans-retinol, which binds to retinol-binding protein. It then enters your bloodstream, at which point your body can use it (5Trusted Source).

SUMMARY
“Vitamin A” is the generic term for a group of fat-soluble compounds found in both animal and plant foods.

Functions in your body
Vitamin A is essential for your health. It supports cell growth, immune function, fetal development, and vision.

Perhaps one of the best-known functions of vitamin A is its role in vision and eye health.

Retinal, the active form of vitamin A, combines with the protein opsin to form rhodopsin, a molecule necessary for color vision and low light vision (6).

It also helps protect and maintain the cornea, which is the outermost layer of your eye, and the conjunctiva, a thin membrane that covers the surface of your eye and the inside of your eyelids (7Trusted Source).

Additionally, vitamin A helps maintain surface tissues such as your skin, intestines, lungs, bladder, and inner ear.

It supports immune function by supporting the growth and distribution of T cells, a type of white blood cells that protect your body from infection (8).

What’s more, vitamin A supports skin cell health, male and female reproductive health, and fetal development (9Trusted Source).

SUMMARY
Vitamin A is needed for eye health, vision, immune function, cell growth, reproduction, and fetal development.

Health benefits
Vitamin A is an important nutrient that benefits health in many ways.

Potent antioxidant
Provitamin A carotenoids such as beta carotene, alpha carotene, and beta cryptoxanthin are precursors of vitamin A and have antioxidant properties.

Carotenoids protect your body from free radicals — highly reactive molecules that can harm your body by creating oxidative stress (10Trusted Source).

Oxidative stress has been linked to chronic conditions such as diabetes, cancer, heart disease, and cognitive decline (11Trusted Source).

Diets high in carotenoids are associated with a lower risk of many of these conditions, such as heart disease, lung cancer, and diabetes (12Trusted Source, 13Trusted Source, 14Trusted Source).

Essential for eye health and preventing macular degeneration
As mentioned above, vitamin A is essential to vision and eye health.

Adequate dietary intake of vitamin A helps protect against certain eye diseases, such as age-related macular degeneration (AMD).

Studies show that higher blood levels of beta carotene, alpha carotene, and beta cryptoxanthin may reduce your risk of AMD by up to 25% (15Trusted Source).

This risk reduction is linked to carotenoid nutrients’ protection of macular tissue by lowering levels of oxidative stress.

May protect against certain cancers
Due to their antioxidant properties, carotenoid-rich fruits and vegetables may protect against certain types of cancer.

For example, a study in more than 10,000 adults found that smokers with the highest blood levels of alpha carotene and beta cryptoxanthin had a 46% and 61% lower risk of dying from lung cancer, respectively, than nonsmokers with the lowest intake of these nutrients (16Trusted Source).

What’s more, test-tube studies demonstrate that retinoids may inhibit the growth of certain cancer cells, such as bladder, breast, and ovarian cancer cells (17Trusted Source).

Vital for fertility and fetal development
Vitamin A is essential for both male and female reproduction because it plays a role in sperm and egg development.

It’s also critical for placental health, fetal tissue development and maintenance, and fetal growth (9Trusted Source).

Therefore, vitamin A is integral to the health of pregnant people and their developing babies, as well as people who are trying to become pregnant.

Boosts your immune system
Vitamin A impacts immune health by stimulating responses that protect your body from illnesses and infections.

Vitamin A is involved in the creation of certain cells, including B cells and T cells, which play central roles in immune responses that guard against disease.

A deficiency in this nutrient leads to increased levels of pro-inflammatory molecules that diminish immune system response and function (18Trusted Source).

SUMMARY
Vitamin A positively affects health by keeping oxidative stress in check, boosting your immune system, and protecting against certain diseases.

Deficiency
Though vitamin A deficiency is rare in developed countries such as the United States, it’s common in developing countries, where populations may have limited access to food sources of preformed vitamin A and provitamin A carotenoids.

Vitamin A deficiency can lead to severe health complications.

According to the World Health Organization, vitamin A deficiency is the leading cause of preventable blindness in children worldwide (19Trusted Source).

Vitamin A deficiency also increases the severity and risk of dying from infections like measles and diarrhea (20, 21Trusted Source).

Additionally, research has found that vitamin A deficiency raises the risk of anemia and death in pregnant women and negatively impacts the fetus by slowing growth and development (22Trusted Source).

Less severe symptoms of vitamin A deficiency include skin issues such as hyperkeratosis and acne (23, 24Trusted Source).

Certain groups — such as premature infants, people with cystic fibrosis, and pregnant or breastfeeding people in developing countries — are more at risk of vitamin A deficiency (25).

SUMMARY
Vitamin A deficiency can lead to blindness, increased infection risk, pregnancy complications, and skin issues.

Food sources
There are many dietary sources of both preformed vitamin A and provitamin A carotenoids.

Preformed vitamin A is more readily absorbed and utilized by your body than plant-based sources of provitamin A carotenoids.

Your body’s ability to effectively convert carotenoids, such as beta carotene, into active vitamin A depends on many factors — including genetics, diet, overall health, and medications (26Trusted Source).

For this reason, those who follow plant-based diets — especially vegans — should be vigilant about getting enough carotenoid-rich foods.

Foods highest in preformed vitamin A include:

egg yolks
beef liver
liverwurst
butter
cod liver oil
chicken liver
salmon
cheddar cheese
liver sausage
king mackerel
trout
Foods high in provitamin A carotenoids like beta carotene include (27):

sweet potatoes
pumpkin
carrots
kale
spinach
dandelion greens
collard greens
winter squash
cantaloupe
papaya
red peppers
SUMMARY
Preformed vitamin A exists in animal foods like liver, salmon, and egg yolks, while provitamin A carotenoids are found in plant foods, including sweet potatoes, kale, and carrots.

Toxicity and dosage recommendations
Just as vitamin A deficiency can negatively impact health, getting too much can also be dangerous.

The Recommended Dietary Allowance (RDA) for vitamin A is 900 mcg and 700 mcg per day for men and women, respectively. This intake level is easy to reach if you consume plenty of whole foods (28Trusted Source).

However, to prevent toxicity, it’s important not to exceed the Tolerable Upper Intake Level (UL) of 10,000 IU (3,000 mcg) per day for adults (28Trusted Source).

Though it’s possible to consume excessive preformed vitamin A through animal-based sources like liver, toxicity is most commonly linked to excessive supplement intake and treatment with certain medications, such as isotretinoin (29Trusted Source).

Since vitamin A is fat-soluble, it’s stored in your body and can reach unhealthy levels over time.

Taking too much vitamin A can lead to serious side effects and can even be fatal if you ingest extremely high doses.

Acute vitamin A toxicity occurs over a short time period when a single excessively high dose of vitamin A is consumed. Chronic toxicity occurs when doses more than 10 times the RDA are ingested over a longer time span (30Trusted Source).

The most common side effects of chronic vitamin A toxicity — often referred to as hypervitaminosis A — are:

vision disturbances
joint and bone pain
poor appetite
nausea and vomiting
sunlight sensitivity
hair loss
headache
dry skin
liver damage
jaundice
delayed growth
decreased appetite
confusion
itchy skin
Though less common than chronic vitamin A toxicity, acute vitamin A toxicity is associated with more severe symptoms, including liver damage, increased cranial pressure, and even death (31Trusted Source).

What’s more, vitamin A toxicity can negatively impact the health of pregnant people and their babies and may lead to fetal development irregularities (9Trusted Source).

To avoid toxicity, steer clear of high dose vitamin A supplements.

The UL for vitamin A applies to animal-based food sources of vitamin A and to vitamin A supplements.

A high intake of dietary carotenoids is not associated with toxicity, though studies link beta carotene supplements with an increased risk of lung cancer and heart disease in people who smoke cigarettes (32Trusted Source).

Since too much vitamin A can be harmful, consult a healthcare professional before taking vitamin A supplements.

SUMMARY
Vitamin A toxicity may have negative effects such as liver damage, vision disturbances, nausea, and even death. Do not take high dose vitamin A supplements unless a healthcare professional prescribes them for you.

The bottom line
Vitamin A is a fat-soluble nutrient vital to immune function, eye health, reproduction, and fetal development.

Both deficiency and surplus intake may cause severe side effects. Therefore, while it’s crucial to meet the RDA of 700–900 mcg daily for adults, it’s also essential not to exceed the daily upper limit of 3,000 mcg.

A healthy, balanced diet is a great way to provide your body with a safe amount of this essential nutrient.

vitamin e

Vitamin E

Foods rich in vitamin E such as wheat germ oil, dried wheat germ, dried apricots, hazelnuts, almonds, parsley leaves, avocado, walnuts, pumpkin seeds, sunflower seeds, spinach and bell pepper

Vitamin E is a fat-soluble vitamin with several forms, but alpha-tocopherol is the only one used by the human body. Its main role is to act as an antioxidant, scavenging loose electrons—so-called “free radicals”—that can damage cells. [1] It also enhances immune function and prevents clots from forming in heart arteries. Antioxidant vitamins, including vitamin E, came to public attention in the 1980s when scientists began to understand that free radical damage was involved in the early stages of artery-clogging atherosclerosis, and might also contribute to cancer, vision loss, and a host of other chronic conditions. Vitamin E has the ability to protect cells from free radical damage as well as reduce the production of free radicals in certain situations. However, conflicting study results have dimmed some of the promise of using high dose vitamin E to prevent chronic diseases.

Recommended Amounts

The Recommended Dietary Allowance (RDA) for vitamin E for males and females ages 14 years and older is 15 mg daily (or 22 international units, IU), including women who are pregnant. Lactating women need slightly more at 19 mg (28 IU) daily.

Vitamin E and Health

Heart disease

CancerAge-related vision diseasesCognitive function and neurodegenerative diseases

Food Sources

Vitamin E is found in plant-based oils, nuts, seeds, fruits, and vegetables.

  • Wheat germ oil
  • Sunflower, safflower, and soybean oil
  • Sunflower seeds
  • Almonds
  • Peanuts, peanut butter
  • Beet greens, collard greens, spinach
  • Pumpkin
  • Red bell pepper
  • Asparagus
  • Mango
  • Avocado

Signs of Deficiency

Because vitamin E is found in a variety of foods and supplements, a deficiency in the U.S. is rare. People who have digestive disorders or do not absorb fat properly (e.g., pancreatitis, cystic fibrosis, celiac disease) can develop a vitamin E deficiency. The following are common signs of a deficiency:

  • Retinopathy (damage to the retina of the eyes that can impair vision)
  • Peripheral neuropathy (damage to the peripheral nerves, usually in the hands or feet, causing weakness or pain)
  • Ataxia (loss of control of body movements)
  • Decreased immune function

Toxicity

There is no evidence of toxic effects from vitamin E found naturally in foods. Most adults who obtain more than the RDA of 22 IU daily are using multivitamins or separate vitamin E supplements that contain anywhere from 400-1000 IU daily. There have not been reports of harmful side effects of supplement use in healthy people. However, there is a risk of excess bleeding, particularly with doses greater than 1000 mg daily or if an individual is also using a blood thinning medication such as warfarin. For this reason, an upper limit for vitamin E has been set for adults 19 years and older of 1000 mg daily (1465 IU) of any form of tocopherol supplement. [1]

Did You Know?

Due to occasional reports of negative health effects of vitamin E supplements, scientists have debated whether these supplements could be harmful and even increase the risk of death.

Researchers have tried to answer this question by combining the results of multiple studies. In one such analysis, the authors gathered and re-analyzed data from 19 clinical trials of vitamin E, including the GISSI and HOPE studies [48]; they found a higher rate of death in trials where patients took more than 400 IU of supplements a day. While this meta-analysis drew headlines when it was released, there are limitations to the conclusions that can be drawn from it. Some of the findings were based on very small studies. In some of these trials, vitamin E was combined with high doses of beta-carotene, which itself has been related to excess mortality.  Furthermore, many of the high-dose vitamin E trials included in the analysis included people who had advanced heart disease or Alzheimer’s disease. Other meta-analyses have come to different conclusions. So it is not clear that these findings would apply to healthy people. The Physicians’ Health Study II, for example, did not find any difference in death rates between the study participants who took vitamin E and those who took a placebo. [12]

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