Advertisement
Quick Fact
Vitamin B is considered to be non-toxic, and harmful effects have not been observed even after the administration of doses that are higher than the recommended intake. However, high doses of vitamin B supplements could sometimes cause transient effects.
Vitamin B is a group of eight water-soluble vitamins called vitamin B1 (thiamine), B2 (riboflavin), B3 (niacin), B5 (pantothenic acid), B6 (pyridoxine), B7 (biotin), B9 (folic acid) and B12 (cobalamin). Out of these, the most commonly used individual vitamins comprise vitamin B1, B2, B6 and B12. The body's requirements for this vitamin can be easily met if one follows a healthy and balanced diet. However, people with poor dietary habits could suffer from a deficiency. Under such circumstances, one could either have food items rich in this vitamin or take vitamin supplements. Whether you take individual vitamins from B-complex family or B-complex capsules, don't increase the dosage without consulting your doctor. Taking this vitamin in doses that are higher than the recommended dietary allowance or tolerable upper intake level could cause health problems.

Overdose of Vitamin B

Though this vitamin is water-soluble and excess vitamin is flushed out through urine, vitamin supplements must be taken as per the prescribed dosage. Certain side effects could arise if one takes this vitamin in large doses. Here are some of the common side effects that may arise if vitamin B is taken in doses higher than the RDA for a long period.

Vitamin B1
This member of the B-complex family is also known as thiamine. It is also referred to as the morale vitamin because it impacts the nervous system in a positive manner. It also helps in the conversion of carbohydrates into energy and keeps the mucus membranes in good condition. Though the benefits of this vitamin are numerous, that does not mean that you pop these pills whenever you want.

RDA
  • The recommended dietary allowance (RDA) of thiamine for infants below the age of 6 months is 0.2 mg, while infants who fall in the age group of 6 to 12 months is 0.3 mg.
  • For children in the age group of 1 to 3 years and 3 to 8 years, the RDA is 0.5 mg and 0.6 mg respectively.
  • For boys and girls in the age group of 9 to 13 years, RDA is 0.9 mg.
  • For males and females above the age of 14 years, RDA is 1.2 and 1 mg respectively.
  • The RDA for pregnant women and nursing mothers is 1.4 mg.
Side Effects
One must ensure that one takes this vitamin as per the aforementioned RDA. If a person takes it in larger doses for a long time, it may cause skin rashes, hypersensitivity and high blood pressure. Its positive impact on the brain and heart will be reversed if you don't adhere to the dosage prescribed by the doctor. You might feel agitated and experience heart palpitations.

Vitamin B2
This member of the B-complex family is also called riboflavin. It is essential for keeping your eyes and skin in a good condition. It also helps in maintaining a strong immune system and regulates the growth of red blood cells. If you are suffering from a riboflavin deficiency, make sure that you take it in prescribed dosage.

RDA
  • The recommended dietary allowance (RDA) of riboflavin for infants below the age of 6 months is 0.2 mg, while infants who fall in the age group of 6 to 12 months is 0.4 mg.
  • For children in the age group of 1 to 3 years and 3 to 8 years, the RDA is 0.5 mg and 0.6 mg respectively.
  • For boys and girls in the age group of 9 to 13 years, RDA is 0.9 mg.
  • For males and females above the age of 18 years, RDA is 1.3 and 1.1 mg respectively.
  • The RDA for pregnant women and nursing mothers is 1.4 mg and 1.6 mg respectively.
Side Effects
One must ensure that one takes this vitamin as per the prescribed dosage. Taking it in large doses could give rise to side effects such as fatigue, vomiting, low blood pressure, nausea or anemia.

Vitamin B3
Also known as niacin, this vitamin helps in the synthesis of DNA. It also facilitates the release of energy from carbohydrates, fats and proteins. It promotes healthy skin and helps in keeping the nerves in a good condition. It is also required for proper secretion of bile and stomach fluids.

RDA
  • The recommended dietary allowance (RDA) of niacin for infants below the age of 6 months is 2 mg, while infants who fall in the age group of 6 to 12 months is 4 mg.
  • For children in the age group of 1 to 3 years and 3 to 8 years, the RDA is 6 mg and 8 mg respectively.
  • For boys and girls in the age group of 9 to 13 years, RDA is 12 mg.
  • For males and females above the age of 18 years, RDA is 16 mg and 14 mg respectively.
  • The RDA for pregnant women and nursing mothers is 18 mg and 17 mg respectively.
  • Though the tolerable upper limit lies between 10 mg to 35 mg, the therapeutic range could be about 2,000 mg.
Side Effects
An overdose of this vitamin could cause high blood sugar, elevated levels of stomach acid or uric acid. Other side effects could include flushing, skin rash, joint pain, insomnia, headaches, nausea or vomiting.

Vitamin B6
Also known as pyridoxine, this vitamin helps in the formation of antibodies and strengthens the immune system. It is also responsible for the formation of niacin in the body. It helps in the synthesis of certain proteins, hormones and neurotransmitters. It plays a vital role in the metabolism of fats and proteins. It is also required for the healthy functioning of the nervous system.

RDA
  • The recommended dietary allowance (RDA) of niacin for infants below the age of 6 months is 0.1 mg, while infants who fall in the age group of 6 to 12 months is 0.4 mg.
  • For children in the age group of 1 to 3 years and 3 to 8 years, the RDA is 0.5 mg and 0.6 mg respectively.
  • For children aged between 9 to 13 years, RDA is 1 mg.
  • For males and females above the age of 18 years, RDA is 1.3 mg.
  • The RDA for pregnant women and nursing mothers is 1.9 mg and 2 mg respectively.
  • Though the tolerable upper limit lies between 30 mg to 100 mg, the therapeutic range could lie in the range of 100 mg to 2,000 mg.
Side Effects
Taking this vitamin in large amounts could have an adverse impact on your nerves. You might experience a tingling sensation or numbness in your hands and feet. It could even lead to serious health problems like high blood pressure, low blood sugar, fatigue, mood swings, heart palpitations, cramps, insomnia or restlessness.

Vitamin B12
This vitamin is also called cobalamin. People who complain about feeling tired all the time are usually asked to take this vitamin. This vitamin certainly helps those suffering from chronic fatigue. It can boost one's energy levels. It helps in maintaining a healthy nervous system and aids in speeding up metabolism. It also regulates the growth of red blood cells.

RDA
  • The recommended dietary allowance (RDA) of cobalamin for infants below the age of 6 months is 0.4 mcg, while infants who fall in the age group of 6 to 12 months is 0.5 mcg.
  • For children in the age group of 1 to 10 years, the RDA ranges between 0.7 mcg to 2 mcg.
  • For children aged 11 and above and adults, the RDA is 2.4 mcg.
  • The RDA for pregnant women and nursing mothers is 2.6 mcg and 2.8 mcg respectively.
Side Effects
The absorption of this vitamin decreases with age which is why aged people might need to take this in form of supplements. Though a person is not likely to overdose on this vitamin as it is water-soluble, excess of anything is bad. If you have been experiencing a tingling sensation on the right side of your body, that might be one of the warning signs. Other side effects include insomnia, panic attacks, heart palpitations or hyperthyroidism.
  • Vitamin B-complex family also includes other vitamins. Taking niacin in larger doses could result in insomnia, heartburn, high blood sugar or vomiting.
  • An overdose of pantothenic acid could lead to depression or dehydration.
  • If you have been overdosing on biotin, you might get skin rashes or experience a rise in your blood sugar level.
  • Taking large doses of Vitamin B8 might cause liver/ kidney problems, vomiting or high blood pressure.
  • Taking folic acid in doses higher than the RDA could cause bloating, anemia or decreased appetite.
  • Excess of vitamin B10 could cause a dip in the estrogen levels. It could also lead to liver problems or hypothyroidism.
  • Intake of large doses of vitamin B11 might lead to symptoms such as vomiting, skin rashes, high blood pressure or kidney/liver problems.
After going through these aforementioned side effects, you would have understood how important it is to take these vitamins in the prescribed dosage. You can avoid health risks associated with a vitamin B overdose by taking these supplements as per the prescribed dosage. A person who has been taking these supplements must seek medical help on experiencing any of the aforementioned side effects.

Disclaimer: This Buzzle article is for informative purposes only, and should not be used as a replacement for expert medical advice.