Can Vitamin B Cause A False Positive Drug Test?

Can Vitamin B Cause A False Positive Drug Test?


Yes. If you are taking vitamin B supplements regularly, there are chances you might get positive drug test results for THC. 

Quantitative and qualitative assessments of Riboflavin by NCBI indicated that 80% of people who took 25mg and 50mg showed positive results within 24 to 36 hours of intake.

Taking too much vitamin B supplements will also make you fail your drug test. Learn more about how vitamin B affects your drug test, when you should stop taking B12 before a test, How long it takes B12 to leave your system, and tips to avoid a failed drug test due to vitamin B supplement consumption. 

Table Of Contents:

How Does Vitamin B Affect Your Drug Test?

Vitamin B is a significant complex that helps in regulating enzymes and break down carbohydrates and fats. But, you must understand that this mineral is water soluble and must be excreted from the body through urine when taken in large amounts.

Meaning, When you consume too many vitamin B supplements, it may produce false positive urine drug test results. 

Vitamin B2 contains riboflavin as an active ingredient which may be made up of hemp seed oil. Hemp seed oil, in turn, may cause a false positive drug test. Riboflavin is also found in other over-the-counter medicines such as Liv 52, B-12, and calcium supplements.

How Riboflavin work?

When you take vitamin B2, the riboflavin breaks down into Flavin mononucleotide (FMN), which further breaks into Flavin adenine dinucleotide (FAD). FAD can bind with CBD and THC metabolites in the urine.

Because FAD is made up of Sulfur, it can bind with CBD and THC metabolites in the urine. The reaction creates an entirely new compound that lab tests can quickly identify.

So, taking too many vitamin B supplements may fail a urine drug test due to these metabolites in your urine. Furthermore, most riboflavin drugs give a strong yellow tint to the urine, thus giving a false impression that you have used marijuana. 

Similarly, Cobalamin may also promote false positive drug tests. A standard drug test may not identify the drug traces, but a confirmatory test can identify cobalamin as THC in your urine. Cobalamin intake through food will scarcely show up in your drug test unless you take cobalamin vials or injections.

Specific vitamin B12 supplements and over-the-counter medicines may contain THC in them, which can cause a false positive during your drug test. So, it is crucial to buy prescribed vitamin B12 supplements than taking OTC drugs.

How Much Vitamin B12  Is Too Much?

The amount of vitamin B12 you consume should be determined by your doctor. However, it would help if you ensured that the amount is optimal to avoid a false positive result. You should not take Over-The-Counter vitamin B12 supplements since that can affect the test results and cause a false positive drug screen. 

How Long Does It Take B12 to Leave Your System?

Generally, Vitamin B12 stays in your body for a longer time, say 1.5 to 3 years, before it leaves the body. 

But that will not show up in your drug test. 

Because most of the B12 will be stored in your liver and your stomach lining, helping your stomach in absorbing minerals and vitamins essential for the body. 

You might fail your drug test only when you take an excessive amount of B12, either through supplements or through vials or injections. Your body will release unused or unnecessary amounts of B12 through urine, and that might show up in your drug test as a false positive for THC.

To summarize, vitamin B12 taken via food or natural means will not affect your drug test results. You might get false positives for THC only when you consume OTC vitamin B12 tablets without a prescription. 

Even if you take it based on a prescription, you might get positive results. To prevent embarrassment, report your prescription to your MRO before your drug test. This will help him/her assess the results accordingly.

When Should I Stop Taking B12 Before A Drug Test?

There are two ways to decide when to stop taking B12 before your drug test

  1. If you are taking vitamin b12 supplements or tablets on prescription, you may indicate your vitamin B12 intake to your tester or MRO during your 5 panel urine drug test
  2. You can visit your physician if your drug test is nearing. Your doctor might recommend you lower the dosage or stop the dosage for a considerable amount of time. 

But the 2nd option might not be a recommended step when you advance in your career. Reporting your B12 intake to the MRO will be the best option.

But there are some tips to avoid a failed drug test while taking Vitamin B12. But it will not eliminate the drug metabolites. Instead, you may deduce them below the cut-off levels.

Tips To Avoid A Failed Drug Test While Consuming Vitamin B Supplements

Apart from talking to your physician, you can follow these below-mentioned tips that may help you balance your vitamin B12 levels if your drug test is coming up.

  1. Drink lots of water
  2. Take the prescribed amount of vitamin B12. Avoid taking OTC vitamin supplements.
  3. Work out 4 to 5 times a week.
  4. Add protein and fiber to your diet.
  5. Avoid alcohol intake.

Remember, this will not completely eliminate the vitamin B traces in your urine. It might create a balance in your metabolism so that a stable amount of vitamin B is maintained in your body.


Vitamin B might show up positive results for THC. If you are taking B in any form on a prescription, report it to your MRO. 

You can also check with your doctor for any chances to reduce consumption. But if you are taking vitamin B12 OTC, it is better to stop using it to pass your drug test. 

You can follow the recommended tips that may help you during the process. 


Can I Take Vitamin B While On The Detox Program?

Yes, you can take vitamin B with the detox program, but you should make sure that the amount is minimal. The detox program is meant to flush out toxins from your body, so taking too much vitamin B can increase the concentration of toxins in your system.

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