Vitamin B is not just a vitamin, but an entire complex of vitamins. What happens to the body in the event of an overdose and what you should pay particular attention to.
vitamin B is not the same as vitamin B. There are a total of eight different B vitamins that can have similar but also very different effects in the body. They are all water-soluble vitamins and are actually excreted from the body through the urine in the event of an overdose – but it’s not quite that simple.
Overdose: Which B vitamins are there?
- Vitamin B1 (thiamine) supports energy metabolism. Foods with vitamin B 1 include oatmeal, peanuts and pork.
- Vitamin B2 (riboflavin, lactoflavin) protects cells from oxidative stress. Foods high in vitamin B2 include almonds and liver.
- Vitamin B3 (niacin) supports the body in energy metabolism and is important for DNA repair. Foods high in vitamin B3 include peanuts, liver and porcini mushrooms.
- Vitamin B5 (pantothenic acid) helps the body produce energy. Foods high in vitamin B5 include chicken, avocado and whole grains.
- Vitamin B6 (pyridoxine, pyridoxamine and pyridoxal) supports the body in protein and amino acid metabolism and helps in the formation of red blood cells. Foods high in vitamin B6 include fish, liver and bananas.
- Vitamin B7 (biotin) is good for skin, hair and the psyche. Foods high in vitamin B7 include liver, cod and hazelnuts.
- Vitamin B9 (Folic acid/folate) is important for cell division. The daily requirement increases, especially during pregnancy. Groceries Liver, mango and spinach are high in folic acid.
- Vitamin B12 (cobalamin) is important for the formation of red blood cells and nerve cells. The vitamin is only found in animal foods such as liver or cheese.
Can you overdose on B vitamins?
An overdose of B vitamins is possible, but rare, as the body normally excretes the excess. An excess can be recognized by the color of the urine: it turns neon yellow. According to the German Nutrition Society (DGE), B vitamins cannot be overdosed through natural food. The coloring usually comes from dietary supplements. If you take too many of them, you may develop symptoms of vitamin toxicity. High doses may be prescribed by a doctor for certain illnesses. If you do not tolerate the vitamin well, you should consult with him.
What are the symptoms of an overdose?
Symptoms of toxicity may be nonspecific and may include dizziness, nausea, or diarrhea. The medical encyclopedia MSD Manual lists symptoms for two B vitamins that can occur at very high doses. These are:
- vitamin B3 (niacin): hot flashes, itching, gout, increased blood sugar levels; rarely the liver can also be damaged
- vitamin B6: Numbness in arms and legs due to nerve damage (neuropathy)
Overdose: Which B vitamins should you be careful with?
The Bavarian State Office for Health and Food Safety warns against taking too much vitamin B6 every day. From 500 milligrams per day, a “toxicological potential for adults can be clearly recognized.” Long-term overdose can cause nerve damage, which, according to the MSD Manual, can even affect the ability to walk.
Vitamin B12 is also not entirely harmless. Usually excess is not harmful, people with liver disease should quarks.de but be careful. In addition, the risk of long-term intake of vitamin B12 is continually discussed among experts. According to the German Cancer Research Center, this may increase the risk of lung cancer. “According to the study, the biggest disadvantage was for men who had consumed the highest dose of (…) more than 55 µg of vitamin B12 per day on average over 10 years.” However, these values are far above the DGE’s recommended daily requirement of 4 micrograms.
In rare cases, an overdose of niacin can damage the liver. However, toxicity can also lead to rashes and gastrointestinal problems.
Based on current studies, the Federal Institute for Risk Assessment (BfR) formulates maximum quantity recommendations, so-called Tolerable Upper Intake Levels (UL), which should, if possible, not be exceeded in the long term. For vitamin B1, B2 and B5, the ULs were abolished because “no adverse health effects were observed, even when consumed in quantities well above the recommended intake,” according to a 2021 press release. ULs have also not been formulated for biotin (vitamin B7). Anyone who does a laboratory test should inform their doctor if they are taking biotin through dietary supplements. The vitamin can distort blood values. According to the BfR, when taking dietary supplements you should not exceed the following dosages:
vitamin B3 (niacin): Daily requirement for adults according to the DGE: 11 to 16 mg
- UL Nicotinamide: 160 mg per day
- UL Nicotinic Acid: 4 mg per day
vitamin B6: 25 mcg; Daily requirement for adults: 4 µg
Folic acid: 200 mcg; Daily requirement for adults: 300 µg
vitamin B12: 25 mcg; Daily requirement for adults: 4.0 µg
Important to note: The BfR ULs are calculated based on various factors. The values always refer to a balanced diet with additional intake of nutritional supplements. As an example of vitamin B12: It is safe to consume 100 µg of vitamin B12 in addition to regular food. Since the BfR assumes that this occurs in equal parts via dietary supplements and fortified foods and that a so-called uncertainty factor is taken into account, the result is a UL of 25. However, anyone who exceeds this value once does not have to fear toxicity. In addition, the values do not apply to people who suffer from a vitamin deficiency or other medical impairments.
This applies to all formulated maximum amounts, including folic acid. According to the National Institute of Health, up to 1000 µg of folic acid per day is considered safe. An overdose of folic acid can damage the immune system in the long term.
How do you determine if nutritional supplements are dosed too high?
High-quality dietary supplements should indicate the reference amounts, abbreviated as RM, for the ingredients. The information is usually given in percentages. If a tablet has an RM of 300 percent for a certain vitamin, the daily requirement is far exceeded. This is usually not a problem for a certain period of time and after consulting your doctor, but over a longer period of time, caution is advised if the values are high.