Vitamin B12 and Urine Color

There is a link between urine color and vitamins.
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Passing urine is such a frequent, routine activity that many people may pay no attention to the color of their urine. But it might be slightly harder to ignore if you begin to pass bright yellow pee. There is a link between vitamins and urine color, particularly vitamin supplements containing B12.


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Vitamin B12: Urine

There are varying forms of vitamin B12, but the two most commonly used to treat deficiencies are cyanocobalamin and hydroxocobalamin. Both of these forms of B12 have an effect on the color of urine.


A June 2017 study published in the Journal of Anesthesia found that red urinary discoloration was present following the use of hydroxocobalamin to treat vasoplegic syndrome. A February 2017 study published in the Journal of General Internal Medicine said hydroxocobalamin treatment induced "wine-colored" urine in a patient — the urine turned a deep reddish purple.


This reddish discoloration found after administering hydroxocobalamin to the body is from the color of the vitamin itself, further providing a link between vitamins and urine color. Similar bright yellow pee caused by the color pigment of riboflavin (vitamin B2), the red discoloration found in B12 urine is from the red pigmentation of hydroxocobalamin. This pigmentation may also transfer to the skin.



If you see red discoloration in your own urine, have it checked out by your medical professional. Though discoloration caused by hydroxocobalamin is entirely harmless, red urine can be symptomatic of much more serious conditions such as a urinary tract infection, kidney stones and even cancer.

Vitamin B12 Benefits

Vitamin B12 is necessary for numerous essential bodily functions, from providing the body with enough energy from the food it digests all the way to protecting and ensuring the health of the nervous system.

The National Institutes of Health and the Mayo Clinic explain the benefits of healthy levels of vitamin B12:

  • Red blood cells: The production and health of red blood cells hinge on vitamin B12. Without the necessary amounts of the vitamin, red blood cells are unable to split and therefore become enlarged, making it harder for them to carry oxygen around the body. Left untreated, this could lead to pernicious anemia, which in turn could lead to cardiovascular disease.
  • The nervous system: Vitamin B12 helps maintain the health and function of the nervous system by preserving the myelin sheath, a protective layer found around all nerves. Without this protective layer, nerves are vulnerable to damage and degradation.
  • Cell metabolism: The process of metabolizing proteins and fats into glucose for the body to use as energy is reliant on vitamin B12 being present in the body.
  • Homocysteine regulation: Vitamin B12 helps control the levels of homocysteine in the blood. High levels of homocysteine have been linked to many cardiovascular and blood vessel diseases.

Read more: Vitamin B12 Benefits and Side Effects

Vitamin B12 Deficiency

Vitamin B12 is found in almost all animal products, including meat, eggs and dairy products, so deficiency is exceptionally rare. Most people get their recommended dose of vitamin B12 from diet alone and do not require supplementation.

In addition, despite vitamin B12 being a water-soluble vitamin, it is not expelled as regularly as other vitamins of its kind. Vitamin B12 is stored in the liver, and the body usually keeps several years' worth in reserve, making deficiency even less likely.

Despite this, deficiency still occurs. The National Institutes of Health lists symptoms of vitamin B12 deficiency:

  • Tiredness
  • Weakness
  • Constipation
  • Loss of appetite
  • Weight loss
  • Numbness and tingling in the hands and/or feet
  • Loss of balance
  • Loss of mental ability, such as memory loss

The causes of vitamin 12 deficiency are varied, but it is important to be aware of them because early prevention is essential. If vitamin B12 deficiency goes on for too long, it can lead to detrimental effects such as permanent nerve damage and severe cardiovascular illness.

Harvard Health Publishing describes potential causes of vitamin B12 deficiency:

  • Weight loss surgery: This can affect the body's ability to absorb nutrients and vitamins adequately, which can make it difficult or impossible to get enough vitamin B12 through dietary means.
  • Celiac or Crohn's disease: These conditions involve the digestive system and its ability to absorb vitamin B12, so they may disrupt absorption.
  • Vegetarian and vegan diets: Because vitamin B12 mainly comes from animal products, vegetarians and vegans are at much higher risk of being B12 deficient than meat eaters.
  • Heartburn medication: Dietary vitamin B12 is absorbed after being broken down by stomach acid, and heartburn medication reduces the amount of acid in the body. If the stomach becomes too low on acid, it may not be able to break down enough 12 to absorb the required amount.

A B12 deficiency can be treated through specially strengthened pills or, if a medical professional deems it necessary, through injections.


B12 supplements do not contain enough of the vitamin to reverse deficiency, and should only be used to fortify your dietary intake. If you suspect a B12 deficiency, contact your health care professional as soon as possible.

Do Vitamins Change Urine Color?

Vitamins and urine color are linked due to the natural pigmentation of certain vitamins, which you may see as they pass through your system. If your urine is bright neon yellow, it may not necessarily be cause for concern, especially if it's from supplements you've been taking.

The National Library of Medicine explains that bright yellow pee can be caused by the passing of riboflavin, otherwise known as vitamin B2. If riboflavin is not processed, and therefore is in excess, it is passed through the urine thanks to its water-soluble state. Its yellow pigmentation may alter the color of the urine to appear almost neon yellow.

Vitamin B2 is not alone in this effect — most B complex vitamins and vitamin C also cause urine to appear orange or bright yellow; they are all water soluble and as such pass through the urine if they are in excess.


If your urine appears orange and you also notice you are passing a paler stool than usual, this could be a symptom of liver failure. In this case, contact your health care professional for advice as soon as possible.