We probably don't need to remind you that focusing on vitamin intake—primarily through diet, with the support of a multivitamin—is a good idea. But for many, how those vitamins are absorbed and metabolized is a bit of a question mark.*
The way our bodies absorb different vitamins plays a large role, which is why it can be really helpful to understand the difference between water-soluble and fat-soluble vitamins. Let’s talk about how water-soluble vitamins absorb into the body compared to fat-soluble vitamins, which vitamins are water-soluble, which vitamins are fat-soluble, and what’s worth knowing about each type of vitamin.
What Are Water-Soluble Vitamins?
As the name suggests, a water-soluble vitamin is one that dissolves in water—and as a result, is easily absorbed into the tissues of the body and metabolized more quickly than fat-soluble vitamins.
The majority of vitamins are water-soluble (1): Vitamin B1 (thiamine), Vitamin B2 (riboflavin), Vitamin B3 (niacin), Vitamin B5 (pantothenic acid), Vitamin B6, Vitamin B7 (biotin), Vitamin B9 (folate), Vitamin B12 (cobalamin), and Vitamin C.
Any excess of water-soluble vitamins, like the Vitamin B complex or Vitamin C, are excreted through the urination process. Many B vitamins and Vitamin C can be found in vegetables (like leafy greens and other green vegetables) and fruits (like citrus fruits).
What Are Fat-Soluble Vitamins?
Fat-soluble vitamins dissolve in—you guessed it—fat. These vitamins are absorbed by fat globules within the body and then carried throughout the bloodstream. There are four fat-soluble vitamins, which include Vitamin A, Vitamin D, Vitamin E, and Vitamin K.
Fat-soluble vitamins are found in high-fat food sources like egg yolks, liver, beef, fatty fish, and dairy products. Unlike water-soluble vitamins, any excess of fat-soluble vitamins don’t immediately leave the body. Instead, they’re stored in the liver or fatty tissue for later use (2).
