Can Too Much Vitamin A Hurt You
We need a certain amount of vitamin A, and consuming plant-based carotenoids is generally safe. Because of the way the body processes carotenoids, you cant really overdose of vitamin A by eating fruits and vegetables.
But too much of the animal form of vitamin A preformed vitamin A can cause health problems.
When consumed in excess, preformed vitamin A can cause weakness, headaches, nausea, dry skin, and other symptoms. Over time, a chronic excess of preformed vitamin A can cause joint pain and the decalcification of bone leading to osteoporosis .
So vitamin A supplementation prescribed by a doctor can be a helpful therapy if you suffer from a vitamin A deficiency. But if arent deficient, supplements can be problematic, because its relatively easy for an otherwise healthy, well-nourished person to take in too much preformed vitamin A.
For example, in the United States, a random, national sample of more than 3,000 children found that 97% of toddlers taking multivitamins were getting excessive amounts of vitamin A amounts above the Tolerable Upper Intake Level. Even among toddlers who didnt take supplements, 15% were getting too much vitamin A .
But what, exactly, do we mean by too much vitamin A?
Whats The Best Way To Take Vitamin C
Both experts stress that the best way to take vitamin C is through food. Whole foods contain a vitamin and micronutrient complex which cannot be fully replicated in vitamin supplements, says Dr. Serino. Also, your body absorbs more of the vitamin through food than through a supplement.
In my experience, most people do not need to supplement with vitamin C since it is abundant in food, says Greaves. The best sources of vitamin C are foods like bell pepper, brussels sprouts, strawberries, and citrus fruit. For example: A half cup of raw red pepper has about 95 mg of vitamin C.
If you dont like any of that stuff, you can eat a medium potato and a cup of red cabbage to get your daily dose. If youve got guava around, youll get 206 mg from eating just one!
Make sure to eat a few servings of fruits and vegetables each day, and youll likely have more than enough vitamin C to make your body happy. Its important to know that research doesnt show any benefit of supplementing with vitamin C beyond the recommended daily intake, says Greaves. So more is definitely not better!
Why You Need Vitamin A
Vitamin A is one of the fat-soluble vitamins, along with vitamins D, E, and K. It’s needed for immune system function, normal vision, reproduction, and cell growth. According to the Institute of Medicine, men need about 900 micrograms and women need about 700 micrograms per day. For food label purposes set by the FDA, the daily value for vitamin a is 900 mcg per day.
Although you can take vitamin A supplements, you’re better off getting this essential vitamin from the foods you eat because vitamin A is paired with other essential nutrients for the body. Flip through the slideshow to see my top ten picks for vitamin A.
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Vitamin A Foods That Will Boost Your Health
Like all the other vitamins, vitamin A plays a crucial role in the normal growth and development of the body. There are a number of vitamin A foods, and a balanced diet can provide us with a sufficient amount of this vitamin. However, some people have to take supplements for various medical reasons. Also, its not recommended to take too much vitamin A as this can lead to some severe medical conditions. We have prepared some interesting data on vitamin A, so lets dive in.
Vitamin A In Pregnancy
Having large amounts of vitamin A can harm your unborn baby. So if you are pregnant or thinking of having a baby:
- do not take supplements containing vitamin A, including fish liver oil, except if you are advised to by your GP
- do not eat liver or liver products, such as pâté, because these are very high in vitamin A
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Special Precautions & Warnings
Pregnancy and breast-feedingLIKELY SAFEPOSSIBLY UNSAFE
Excessive use of alcohol: Drinking alcohol may increase vitamin A’s potentially harmful effects on the liver.
Anemia: People who are anemic and have low levels of vitamin A might need to take iron along with a vitamin A supplement to treat this condition.
Disorders in which the body does not absorb fat properly: People with conditions that affect fat absorption, such as celiac disease, short gut syndrome, jaundice, cystic fibrosis, pancreatic disease, and cirrhosis of the liver, are not able to absorb vitamin A properly. To improve vitamin A absorption, these people should use vitamin A preparations that are water-soluble.
A type of high cholesterol called “Type V hyperlipoproteinemia”: This condition might increase the chance of vitamin A poisoning. Do not take vitamin A if you have this condition.
Intestinal infections: Intestinal infections such as hookworm can reduce how much vitamin A the body absorbs.
Liver disease: Too much vitamin A might make liver disease worse. Do not take vitamin A if you have liver disease.
Malnutrition: In people with severe protein malnutrition, taking vitamin A might result in having too much vitamin A in the body.
Zinc deficiency: Zinc deficiency might cause symptoms of vitamin A deficiency to occur. Taking a combination of vitamin A and zinc supplements might be necessary to improve this condition.
Impact Of Vitamin D Levels On Disease Activity In Rrms: Observational Studies
In a prospective longitudinal study from the Netherlands, 25D was measured every 8 weeks for a mean of 1.7 years in 73 patients with RRMS . Fifty-eight patients experienced a total of 139 exacerbations during the study period. Relapse risk was significantly reduced in those with medium and high serum vitamin D levels compared to those with low levels . For each doubling of serum vitamin D concentration from baseline of 10, 20, 30, MS relapse risk decreased by 27%. Although this suggests a beneficial effect of vitamin D on MS, it must be noted that there is also a possibility that conditions associated with MS relapse had an effect on serum vitamin D levels .
Association of vitamin D and relapse risk in MS. The graph shows risk of relapse according to 25D levels, adjusted for age and month of serum measurement. Size of points is proportional to the inverse of the variance .
Reprinted with permission from Wiley Company
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Am I At Risk Of Vitamin A Deficiency
Vitamin A deficiency can make it more difficult for you to see properly, especially at night. It can also make it hard for your body to fight infections.
You may be deficient in vitamin A if your body is unable to absorb it properly from your food. This may happen if you:
- drink a lot of alcohol
- have a medical condition such as anorexia nervosa, liver disease, cystic fibrosis or coeliac disease
- have recently had gastrointestinal surgery
Vitamin A deficiency is usually diagnosed by doing a blood test.
If your vitamin A levels are very low, or your doctor suspects you have a vitamin A deficiency, they may prescribe you vitamin A supplements.
Beta Carotene As A Source Of Vitamin A
The body can change beta carotene into vitamin A so including these sources will also help. The main food sources of beta-carotene are:
- yellow, orange and red vegetables such as carrots, sweet potatoes and red peppers
- green vegetables, such as spinach
- yellow fruit, such as mango, apricots and papaya
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How Much Does This Matter Should I Worry If My Child Has Been Getting Too Much Preformed Vitamin A
In the study of American toddlers, the vast majority of kids taking vitamin supplements were getting too much vitamin A. But that doesnt mean they were suffering adverse effects.
When health agencies set a tolerable upper intake level, they include a safety margin. Typically, the value is set at 2.5-fold lower than the daily intake associated with documented health problems.
Its also not clear how often multivitamin supplements and fortified foods actually deliver what they claim.
For instance, sunlight reduces the potency of retinol, and many childrens vitamins are sold in trasparent plastic bottles. How potent are kids vitamins, really? I havent found any answers to that question. Perhaps researchers will address this point in the future.
Whats more certain, however, is that many children healthy, well-nourished children are taking in more preformed vitamin A than they need. Its wasteful at best.
If a child is consuming lots preformed vitamin A, it may contribute to long-term health problems.
As noted above, chronic over-consumption of preformed vitamin A can cause symptoms of illness, and bone loss.
Vitamin A overdose during can also cause birth defects, which is why prenatal vitamin supplements are supposed to contain beta caroteneNOT preformed vitamin A.
In short, theres no reason to panic. But its wise to be aware of the sources of preformed vitamin A in your childs diet, read labels, and chose vitamin supplements carefully.
Retinol Activity Equivalents And The Vitamin A Daily Value
Since retinol and carotenoids do not offer the same bioavailability, the FDA recently mandated a new way of measuring the vitamin A content of food.
This measurement is called the retinol activity equivalent , which takes the low bioavailability of carotenoids into account.
These new guidelines state that 1 microgram of retinol activity equivalent is equivalent to
- 1 mcg retinol
- 12 mcg beta-carotene
- 24 mcg other carotenoids
In other words, retinol is deemed to be approximately 12x to 24x more valuable as a vitamin A source than carotenoids.
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How Is The Test Used
Vitamin A testing is used to help diagnose a vitamin A deficiency in people with signs and symptoms, such as night blindness, or in people who are at risk of vitamin A deficiency. Testing for this purpose is not common because vitamin A deficiencies are rare in the United States.
Sometimes testing may be used to detect toxic levels caused by consuming large amounts of vitamin A.
Can I Have Too Much Vitamin A
You should not take vitamin A supplements unless your doctor tells you to. Having too much vitamin A in your body can cause serious health problems, including nausea, hair loss, blurred eyesight, orange skin colour and an inability to control body movement.
In pregnant women, too much vitamin A can cause birth defects.
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How To Get More In Your Diet
As long as you eat a variety of whole foods and avoid or limit processed foods, its easy to include more foods with vitamin A in your diet. Here are tips are incorporating vitamin A foods into a variety of meals:
- Top a salad of leafy greens with berries or dried apricots.
- Add beef or chicken liver to chopped meat, or make/buy chicken pate.
- Lightly sauté vegetables like broccoli, kale or spinach in grass-fed butter.
- Have one to two pastured eggs with veggies and roasted sweet potatoes for breakfast.
- Roast winter squash, butternut squash or sweet potatoes tossed in butter in the oven.
Sweet Potato Try Making A Sweet Potato Hash With Sausage And Dill Anna Hoychuk/shutterstock
One large sweet potato baked with skin contains 1,730 mcg of vitamin A .
A serving of sweet potato also has 35.3 milligrams of vitamin C , which plays a key role in bone, muscle, immune, and skin health.
Quick tip: Baked, roasted, or air-fried sweet potatoes serve as a tasty side dish with meats, veggie burgers, or eggs.
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Should I Take More Vitamin C When Im Sick
Many people pop vitamin C pills when they feel a cold coming on. Though vitamin C helps the immune system, it does very little for a cold.
A study from the Australian National University found that vitamin C supplements did not prevent colds at all. Supplementation, in a few cases, helped people get over the cold a little bit faster since about 8 percent of participants had one less day of sickness due to vitamin C.
If you want to play it safe and add more vitamin C when youre sick, its still best to do it through food. Add more citrus or greens. Even if the vitamin C doesnt make a difference, the healthy food will help you feel better.
Dietary Intake Of Vitamin D And Ms Risk
Using data from two large cohorts of the Nurses Health Study involving more than 187,000 women , Munger and colleagues evaluated the association between calculated vitamin D intake from diet or supplements and the risk of developing MS . Women who had a higher intake of dietary vitamin D had a 33% lower incidence of MS compared with those with lower intake. In addition, women who used vitamin D supplements had a 41% reduced risk of developing MS compared to non-users. Having higher levels of 25D also seems to predict a lower risk of MS onset. Using a longitudinal study design, Munger and colleagues evaluated serum vitamin D levels derived from blood samples of seven million US military personnel. Those with 25D levels greater than 100 nmol/L had a 62% lower chance of subsequently developing MS .
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Taking Too Much Vitamin A
According to some research, having more than an average of 1.5mg a day of vitamin A over many years may affect your bones, making them more likely to fracture when you are older.
Older people, particularly women, are already at risk of osteoporosis. This is where your bone density reduces and you have a higher risk of fractures.
If you eat liver or liver pâté once a week, you may be getting more than a daily average of 1.5mg of vitamin A.
If you do not get enough vitamin D, you could be more at risk of the harmful effects of too much vitamin A. People who may be particularly short of vitamin D include:
- pregnant and breastfeeding women
- people aged 65 and over
- people who are not exposed to much sun, for example those who are housebound or confined indoors for long periods
- people with darker skin such as people of African-Carribean and South Asian origin
Many multivitamins contain vitamin A. Other supplements, such as fish liver oil, are also high in vitamin A. If you take supplements containing vitamin A, make sure your daily intake of vitamin A from food and supplements does not exceed 1.5mg. If you eat liver every week, do not take supplements that contain vitamin A.
What Is Being Tested
Vitamin A is a fat-soluble vitamin that is naturally present in many of the foods we eat. Retinol is the primary form of vitamin A in humans. This test measures the level of retinol in the blood.
Vitamin A is an essential nutrient required for healthy vision and skin, bone formation, immune system function, and reproduction. It is required to produce photoreceptors in the eyes and to maintain the lining of the surface of the eyes
Vitamin A is a fat-soluble vitamin that is naturally present in many of the foods we eat. Retinol is the primary form of vitamin A in humans. This test measures the level of retinol in the blood.
Vitamin A is an essential nutrient required for healthy vision and skin, bone formation, immune system function, and reproduction. It is required to produce photoreceptors in the eyes and to maintain the lining of the surface of the eyes and other mucous membranes. A lack of vitamin A can affect night vision, cause eye damage, and in severe cases, lead to blindness. Too much vitamin A can be toxic, causing a range of symptoms, and sometimes leading to birth defects.
In the U.S., vitamin A deficiencies are primarily seen in those with malnutrition, chronic diarrhea, malabsorption disorders such as celiac disease, cystic fibrosis, or chronic pancreatitis, in the elderly, and in those with alcoholism, liver disease and blockage of the bile ducts. Surgery either on the intestine or pancreas can have the similar consequences.
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The Foods Highest In Vitamin A
The best sources of vitamin A are a combination of vegetables, dairy products, fish, and beans.
The top 7 vitamin A foods that are considered an excellent source of the nutrient are:
Here are the TK best vitamin A foods to add to your diet.
Vitamin A content: 6,540 mcg per 3 ounces fried
You might not think liver ever makes it to your plate, but it does if you ever dip into paté or foie gras on a charcuterie board. In three ounces of pan-fried beef liver, you’ll get 726 percent of your daily vitamin A needs. “Liver is the main place extra vitamin A is stored in us and in animals, so if you eat animal liver that’s where a lot of it is,” says Brissette. With that said, liver is also high in saturated fat, so it’s not a nutritionist’s top pickespecially compared to the other options on this list. “If you have enough veggie sources and dairy, you’ll be covered,” says Brissette.
Vitamin A content: 1,910 mcg per 1 cup
If you want to eat more vitamin A foods, you shouldn’t reserve canned pumpkin for the fall months. “Because canned pumpkin is already cooked and blended, you get a higher concentration than when it’s fresh,” says Brissette. To add it to your diet outside of making pumpkin pie, swap plain canned pumpkin as a nutrient-rich replacement for oils in recipes like pumpkin bread or pancakes, mix it in oatmeal, add it to a smoothie, or use it in a soup.
Vitamin A content: 1,130 mcg per medium potato with skin
