Yellow urine and vitamins

After taking a vitamin supplement, most people notice that their urine turns an intense yellow, almost fluorescent. This feature, completely harmless, is mainly linked to the presence of a water-soluble vitamin, called riboflavin or vitamin B2.

When we take a riboflavin-rich multivitamin supplement, not all of the ingested portion is actually absorbed. The surplus, thanks to the water solubility of the substance, is eliminated with the urine, which acquire the classic fluorescent shades. Like all water-soluble vitamins, the body is able to eliminate excess riboflavin without any particular signs of toxicity, however possible when the doses are clearly high. Faced with a daily requirement of about 1.3 mg, intestinal absorption, which occurs in the small intestine, is saturable, so that doses far above the RDA are only useful to produce particularly expensive urine (the maximum absorption capacity is it is around 25 mg).

To reduce the phenomenon of intense yellow coloring of the urine, it is possible to divide the tablet into two parts to be taken at different times of the day, preferably in conjunction with the main meals.