Why does urine turn yellow-green after taking vitamin B2?

Under normal circumstances, yellowish-green urine after taking vitamin B2 is a normal physiological phenomenon. The specific analysis is as follows:

Vitamin B2, also known as riboflavin, has a naturally yellow color due to its yellow pigment content. As a water-soluble vitamin, the excess pigment is excreted from the body through urine after ingestion, causing the urine to appear yellow or greenish-yellow. This is considered a normal physiological response and typically does not require special treatment. Additionally, taking supplements such as 21 Golden Vitamins oral solution or multivitamin tablets may also lead to changes in urine color; therefore, there is generally no need for excessive concern.

During vitamin B2 supplementation, patients are advised to drink plenty of warm water to promote urination, which helps normalize urine color.