Vitamins are very important for health, though you only need them in small amounts and should be able to get a lot of food from what you consume. The question is, can we overdose on Vitamins?
Yes of course. While it is nearly impossible to get too many vitamins from food, you can overdose on some vitamins if you take large doses of supplements for a long time.
Why Can Overdose on Vitamins?
Most of the vitamin supplements you see on store shelves are sold in doses that shouldn't cause any problems as long as you follow label directions.
But sometimes people take much larger amounts of the vitamin, called a "mega-dose," in the hope that the supplement will help prevent or treat certain health problems.
There are two problems with those experienced with mega-dose vitamins. First, there is rarely a scientific reason to take large amounts of vitamins.
Second, you can actually develop health problems if you take mega-dose with multiple vitamins. Usually, the problem can be reversed if you stop taking large doses, but not always, so if you notice that you have been taking large doses of vitamins, please contact your doctor immediately.
Which Vitamins Are Dangerous in Large Doses?
The Food and Nutrition Board of the Division of Health and Medicine of the National Academies of Science, Engineering and Medicine has established the Tolerable Upper Intake Levels (UL) for all vitamins and minerals.
The UL is the highest level of daily nutrient intake that would not pose any risk to a healthy person. Here are the ULs for all vitamins and what can happen if you take too much.
Vitamin A
Vitamin A is an essential nutrient for the body, they are able to promote normal vision health, cell development, and immune system function. Adults need about 700 to 900 micrograms (mcg) per day, and it's found in liver, fish, meat, dairy products, and colorful fruits and vegetables . 2
UL for vitamin A by age:
0 to 3 years : 600mcg
4 to 8 years: 900mcg
9 to 13 years : 1,700mcg
14 to 18 years: 2,800mcg
Adults : 3,000mcg
Since Vitamin A is a fat-soluble vitamin, it is easily stored by your body so it can accumulate over time.
Long-term intake of excessive amounts of vitamin A can cause intracranial pressure, dizziness, nausea, liver damage, headache, rash, joint and bone pain, coma, and even death.
Vitamin C
Vitamin C in the body is able to encourage strong connective tissue and immune system function. It is also an antioxidant that can help prevent free radical damage.
The average adult body needs vitamin C intake of about 75 to 90 milligrams (mg) per day. Vitamin C is found in many fruits and vegetables, but people often take vitamin C supplements in the hopes that they will help ward off colds and flu.
UL for Vitamin C by age:
0 to 12 months: unknown
1 to 3 years : 400mg
4 to 8 years : 650mg
9 to 13 years : 1,200mg
14 to 18 years : 1,800mg
Adult: 2,000 mg
Taking large amounts of vitamin C is not life-threatening, but it can cause diarrhea, nausea, and stomach cramps and has been linked to kidney stones.
Vitamin D
Vitamin D helps your body absorb and utilize calcium, so if you don't get enough vitamin D, you run the risk of weakening bones and osteoporosis, among other things. Most adults need 600 International Units (IU) daily.
You don't get much vitamin D from food, but your body makes it after your skin is exposed to the sun. Vitamin D is a popular supplement, but you can get too much of it if you mega-dose each day.
UL for Vitamin D by age:
0 to 6 months : 1,000 IU
7 to 12 months : 1,500 IU
1 to 3 years : 2,500 IU
4 to 8 years : 3,000 IU
9+ years : 4,000 IU
Taking too much vitamin D in supplement form can increase the level of calcium in your blood, which can be bad for your heart and kidneys. You
You won't get too much vitamin D from overexposure to the sun, and it's very difficult to get too much vitamin D from your diet. Adults need about 15 mg per day.
Vitamin E
Your body needs vitamin E for normal immune system function, and it also functions as an antioxidant and helps prevent the formation of blood clots in your blood vessels. It is found in a variety of foods, but mostly in nuts, seeds, and leafy green vegetables. The average adult needs about 15mg per day.
UL for Vitamin E by age:
0 to 6 months: unknown
7 to 12 months: unknown
1 to 3 years : 200mg
4 to 8 years : 300mg
up to 13 years : 600mg
14 to 18 years : 800mg
Adult : 1000mg
Taking too much vitamin E can increase your risk of bleeding, which is especially important if you have an increased risk of stroke or are taking blood-thinning medications.
Niacin
Niacin helps convert the food you eat into the energy your body needs to do everything you do. Deficiencies are rare because they are found in a wide variety of foods, but are also sold as a supplement that is often used to manage cholesterol levels.
UL for Niacin by age:
0 to 6 months: unknown
7 to 12 months: unknown
1 to 3 years : 10mg
4 to 8 years : 15mg
9 to 13 years : 20mg
14 to 18 years : 30mg
Adult : 35mg
Consuming large amounts of niacin can cause liver damage and affect blood sugar levels in people with diabetes.
In the short term, taking large doses of niacin causes a niacin flush, which, while harmless, is uncomfortable and can be scary.
Vitamin B-6
Your body needs Vitamin B6 to help convert protein and sugar into energy, and it's important for hemoglobin production and nervous system function.
The average adult body requires about 1.3 mg of vitamin B6 per day. It is very difficult to have a B-6 deficiency, so supplements are not necessary, but have been used to reduce homocysteine levels and to help treat depression and carpal tunnel syndrome.
UL for Vitamin B-6 by age:
0 to 6 months: unknown
7 to 12 months: unknown
1 to 3 years : 30mg
4 to 8 years : 40mg
9 to 13 years : 60mg
14 to 18 years : 80mg
Adult: 100mg
Long-term consumption of vitamin B6 supplements can damage the body by causing nerve damage, skin lesions, nausea, and light sensitivity.
Folic acid
Folic acid is a synthetic form of folate, a B-complex vitamin that is important for making DNA, cell division, and growth.
Folate is found in fruits and green vegetables, while folic acid is often used to fortify cereals and breads. The average adult needs about 400mcg daily, but it is also sold as a dietary supplement.
UL for Folic Acid by age:
0 to 6 months: unknown
7 to 12 months: unknown
1 to 3 years: 300mcg
4 to 8 years: 400mcg
9 to 13 years: 600mcg
14 to 18 years : 800mcg
Adults: 1,000mcg
Consuming large amounts of folic acid can make up for a vitamin B-12 deficiency that can cause nerve damage. It is also possible that large amounts of folic acid may increase the risk of colorectal cancer.
Choline
Choline is a B-complex vitamin that the body needs for biological processes and to produce a brain chemical called acetylcholine.
UL for Choline by age:
0 to 6 months: unknown
7 to 12 months: unknown
1 to 8 years : 1,000mg
9 to 13 years : 2,000mg
14 to 18 years : 3,000mg
Adult : 3500mg
Taking too much choline every day can cause fishy body odor, excessive sweating, low blood pressure, and liver problems.
What About Other Vitamins?
The Food and Nutrition Board has not set ULs for vitamin K, thiamin, riboflavin, vitamin B-12, pantothenic acid, or beta-carotene (a plant precursor of vitamin A). That doesn't mean it's okay to take large doses, it's just that the tolerance level hasn't been determined.
