Vitamin B2 Overdose: Is It Safe to Take Too Much Riboflavin?

vitamin B2 overdose

What happens if you take a vitamin B2 overdose? More importantly, is there such a thing as riboflavin overdose or riboflavin toxicity?

Riboflavin (vitamin B2) is one of B vitamin complex, which includes thiamine (vitamin B1), riboflavin (vitamin B2), niacin (vitamin B3), pantothenic acid, vitamin B6, biotin (vitamin B7), folate (folic acid) and vitamin B12.

riboflavin overdose symptoms

Riboflavin is important for your long-term skin, eyes and nervous system health. It also helps the body to release energy from the carbohydrates, proteins and fats that you eat. Being deficient in riboflavin can lead to skin disorders, too much blood, swollen mouth and throat, lesions at the corners of the mouth, swollen and cracked lips, hair loss, problems with reproduction, sore throat, and itchy red eyes.

Your body doesn’t store riboflavin. As such, you can risk getting riboflavin deficiency if you don’t get enough from your diet. That’s why you should eat foods that are high in riboflavin, such as:

  • milk
  • eggs
  • mushrooms
  • plain yoghurt
  • green vegetables (such as asparagus, broccoli, and spinach)
  • fortified foods that have had riboflavin added to them, such as some breakfast cereals, bread, plant-based milk, and grains

It is important to keep these foods out of direct sunlight as UV light can destroy riboflavin.

If you’re interested in vitamin B2 overdose and toxicity, here’s everything you need to know.


How much riboflavin do I need?

The recommended daily doses of riboflavin are as follows:


  • 0-6 months – 0.3mg/daily
  • 7-12 months – 0.4mg/daily


  • 1-3 years – 0.5mg/daily
  • 4-8 years – 0.6mg/daily
  • 9-13 years – 0.9mg/daily

Adolescents and adults:

  • Males 14-18 years – 1.3mg/daily
  • Females 14-18 years – 1mg/daily
  • Men 18 years and over – 1.3mg/daily
  • Women 18 years and over – 1.1mg/daily
  • Pregnant women – 1.4mg/daily
  • Women who are breast feeding – 1.6mg/daily

According to the NHS, taking 40mg or less of riboflavin a day shouldn’t cause harm.

READ ALSO: Vitamin B2 Deficiency: 7 Symptoms to Be Aware Of


What happens if I take too much riboflavin?

Being concerned about vitamin B2 overdose is understandable. After all, too much of anything is never good.

There are two types of vitamins: fat-soluble and water-soluble. Fat-soluble vitamins dissolve in fat and include vitamins such as vitamins A, D, E and K. You can find these vitamins in high-fat foods such as egg yolks, meats (especially liver), oily fish, and dairy.

If you take too much of a fat-soluble vitamin, the excess gets stored in the liver or fatty tissue. Because of this, an overdose of a fat-soluble vitamin can lead to toxic levels of the vitamin in the body. This can put you at a higher risk of developing osteoporosis, tumours and digestive issues.

Riboflavin is a water-soluble vitamin. These vitamins dissolve in water and so are absorbed into the body’s tissues quickly and easily. Most vitamins are water-soluble, including vitamin C and all of the B vitamins. Water-soluble vitamins are found in high levels in vegetables and fruits.

riboflavin overdose

If you take too much of a water-soluble vitamin, like riboflavin, it doesn’t get stored in the body as fat-soluble vitamins do. Instead, it gets removed from the body in your urine. It’s important to remember that this also means that you need to eat water-soluble vitamins regularly as your body can’t store them up.

In other words, your body won’t be affected by vitamin B2 overdose as any riboflavin excess is removed from your body. Even if you take a higher amount than your RDA, it’s unlikely you’ll experience riboflavin overdose symptoms.


What are the side effects of riboflavin overdose?

Riboflavin can cross the placenta barrier and reach the foetus. Riboflavin can also be passed through your breastmilk to your baby. No harmful side effects of vitamin B2 overdose have been reported, however.

The only common side effect found from taking a vitamin B2 overdose is bright yellow urine. This occurs because of the kidneys excreting the excess out into your urine. It might be quite strange to see your urine change colour so dramatically, but this vitamin B2 symptom is not harmful.


Riboflavin overdose and supplements

You should be able to get enough riboflavin in your diet. However, many people find that taking riboflavin supplements can help them make sure they have enough vitamins in their diet.

symptoms of vitamin B2 overdose

The B vitamins all work together to help your body function properly. So if you do decide to find a supplement with riboflavin, it is important to find one that contains all of the B vitamins to make sure that they give you the most health benefits from working together. Most B complex supplements provide 100% of your RDA, so a vitamin B2 overdose is very unlikely.

This will also ensure that you don’t take too much of any one of them, which should help you to avoid any side effects.


Vitamin B2 Overdose

Riboflavin is a water-soluble vitamin. This means that if you take too much, your body will excrete any excess in your urine. Since your body doesn’t store any riboflavin excess, it is not possible to overdose on it. The only side effect of vitamin B2 overdose is that your urine may turn bright yellow (because of your body getting rid of it), but this is not a sign of vitamin B2 toxicity.

It’s important to take a supplement that contains all of the B vitamins to prevent an imbalance in B vitamins in the body.

Always speak to your GP or health care provider before taking a vitamin B complex supplement.

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