Water-Soluble Vitamins vs. Fat-Soluble Vitamins: Know Your Vitamins to Optimize Your Health

Key Points:

  • Getting enough vitamins seems like an obvious choice for better health. However, it’s estimated that almost 95% of people aren’t getting enough vitamins in their diet. This may be due to processed foods and depleted nutrients in crop soil.
  • When supplementing with vitamins, it’s important to recognize the difference between water-soluble vitamins and fat-soluble vitamins. Extra water-soluble vitamins are processed and excreted through the kidneys, but excess fat-soluble vitamins are stored in adipose tissue. 
  • Understanding how vitamins are absorbed into your body is key — and will allow you to get the most out of your foods and supplements.

Do you experience a myriad of unexplained symptoms?

Maybe it’s hair loss. Unexplained headaches. Or occasional gut issues that conveniently act up at the most embarrassing moments. Or maybe you just feel off, and you can’t explain why.

You’ve been to the doctor and done all the tests, but the doctors say everything’s normal (which is defeating since you certainly don’t feel normal).

Now, we can’t diagnose an unknown condition. But we might know something that could help: Restoring deficient nutrients, like vitamins.

Maybe it sounds like an anticlimactic and too-good-to-be-true solution, but hear us out.

It’s estimated that about 95% of the population is not reaching their minimum daily vitamin intake.

We’re not even sure that the “minimum daily intake” (you know, the one we aren’t reaching) is truly enough nourishment for our bodies to thrive. It’s still up for debate in the research. At best, it’s the minimum amount required for adequate function, but likely not enough for optimal function.

So, is a lack of vitamins behind your mystery symptoms? Maybe. Learning about them is the first step to using vitamins as a catalyst for good health.

Table of Contents:

Water-Soluble vs. Fat-Soluble Vitamins: Understanding the Different Types of Vitamins

There are two main types of vitamins your body needs: Fat-soluble vitamins and water-soluble vitamins. It’s vital to understand the difference between the two — especially if you’re taking a daily multivitamin or using individual supplements to optimize your health.

They may seem like “just vitamins” but your understanding of these vitamin types could mean life or death. (It sounds dramatic, but we’re not kidding!)

What Are Fat-Soluble Vitamins?

These are vitamins that are stored in adipose tissue (aka, fat — which explains their name). They may also be stored in the liver and skeletal muscle. This is one of many ways your body prioritizes survival — storing much-needed nutrients for later.

For this reason, a deficiency in fat-soluble vitamins is generally less common than a deficiency in water-soluble vitamins. But it’s certainly not out of the question, especially for vitamins that perform a lot of different functions in the body. A diet rich in processed foods is the perfect recipe for deficiency — even when it comes to stored vitamins.

Recent studies show that more than 40% of people are deficient in vitamin D and up to 90% (!) of Americans aren’t getting enough vitamin E.

Vitamin K2 was only just discovered around the 1930s, and we still don’t entirely understand what it does for the body. What we do know is that it’s primarily found in organ meats and fermented foods — so unless you have a steady diet of those foods, you’re probably not getting enough of it.

Benefits of Fat-Soluble Vitamins

Vitamins may seem trivial (especially to those who are fighting big health battles) but they do so much for the body behind the scenes. Your fat-soluble vitamins contribute to things like:

…and so much more.

List of Fat-Soluble Vitamins

So, exactly what kinds of vitamins are considered fat-soluble? There are only a handful of fat-soluble vitamins, and each is incredibly important:

Risks of Fat-Soluble Vitamins

Vitamins are vitamins. They’re harmless, right? Actually, in the case of fat-soluble vitamins, they can pose a significant threat to your health and wellness when consumed in very high doses, or even lower doses over a long period of time.

Here’s what we mean: Fat-soluble vitamins are stored in your body until they are needed. With the introduction of synthetically produced vitamin supplements, this can be a problem. Vitamin toxicity is a risk that’s much more likely to occur with fat-soluble vitamins (particularly, in supplement form).

Over-indulging in a vitamin D or vitamin A supplement, for example, could induce symptoms of toxicity in your body — and can even become life-threatening.

For this reason, it’s a good idea to supplement fat-soluble vitamins under the supervision of a functional medicine practitioner. Your vitamin levels should be carefully tested and re-tested after a few months to ensure you don’t accidentally reach levels of toxicity. Whenever possible, consume your fat-soluble vitamins from a nutrient-dense diet rather than blindly taking supplements.

What Are Water-Soluble Vitamins?

These vitamins are dissolved in water — and excess levels are expelled through the kidneys and bladder. Have you ever taken a brand new vitamin regime, only to notice the vitamins end up in your urine? (B vitamins are notorious for causing bright yellow urine.) That’s the magic of water-soluble vitamins.

Since our bodies don’t store these vitamins, we need to consume them more frequently. Most minerals are considered water-soluble, too.

Benefits of Water-Soluble Vitamins

Vitamin C, specifically, is a powerful vitamin for immune system function, blood pressure, heart health, memory, and even helps you absorb other nutrients like iron.

B vitamins are directly involved with our cellular health and work to transport other nutrients throughout the body. For something your body doesn’t store, it’s pretty important to make sure you’re eating (or supplementing) enough B vitamins on a daily basis.

List of Water-Soluble Vitamins

These vitamins (along with most minerals) are considered water-soluble:

  • Vitamin C
  • Thiamin (B1)
  • Riboflavin (B2)
  • Niacin (B3)
  • Pantothenic acid (B5) 
  • Pyridoxine (B6)
  • Biotin (B7)
  • Folate (B9)
  • Cobalamin (B12)

… Or, in simpler terms — water-soluble vitamins consist of vitamin C and every form of vitamin B. 

Risks of Water-Soluble Vitamins

Since excess water-soluble vitamins are released through urine, cases of vitamin toxicity due to these vitamins are extremely rare. Functional medicine practitioners are more likely to recommend high doses of water-soluble vitamins since they’re relatively safe.

Still, any supplement should be taken with caution — and if you have any kidney or liver problems (aka problems metabolizing vitamins), you should speak with a healthcare professional before consuming these vitamins. At the end of the day, it’s always best to meet your daily vitamin needs with a food-first approach, and use supplementation to boost your intake when needed.

How to Know You’re Getting Enough Vitamins

Most likely, you aren’t getting enough vitamins in your diet.

But instead of blindly throwing the dart with supplementation, reliable lab testing (our favorite is the Hair Tissue Mineral Analysis) can help you pinpoint exactly what deficiencies are causing your symptoms. Some standard blood tests can also be helpful when looking for vitamin deficiencies, such as testing for vitamin D levels.

If you aren’t able to immediately access a test, then we recommend researching and implementing a nutrient-dense diet. Eat foods that are high in bioavailable vitamins, like beef liver (basically nature’s multivitamin), raw dairy, healthy fats, locally sourced eggs, grass-fed meat, and organically grown fruits and veggies.

The Role of Healthy Fats & Vitamin Absorption

Remember back in the 80s when eating a low-fat diet was considered the epitome of good health? Yikes. This just goes to show that not all diet advice is good advice.

Here’s the thing about eating a low-fat diet: Even if you’re consuming tons of vitamins (both naturally and through supplementation) you probably aren’t absorbing them.

Healthy fats (nuts, seeds, avocados, olives, animal fats, etc.) are directly involved in the absorption and use of fat-soluble vitamins, especially.

So, if you know about a vitamin deficiency and start supplementing or changing your diet to include more of that vitamin, make sure you increase your intake of healthy fats, too. This is why many practitioners advise taking vitamins and minerals with food. 

There’s So Much More to Vitamin Intake Than Meets the Eye

Vitamins are simple. Or, are they? The truth is, we still don’t know everything there is to know about vitamins (vitamin K2 is a great example of this). We’re still conducting studies, learning the many benefits of vitamins, and exploring how to best optimize our daily vitamin intake.

Today, most of us are deficient in the healthy fats we need to absorb vitamins into our bodies. Without healthy fats, vitamin supplements and even nutrient-dense foods can only do so much for us.

One way to optimize your healthy fat intake is to add BodyBio Balance Oil to your diet — a careful mix of omega-6 and omega-3 essential fatty acids to support brain health, aging, and cellular regeneration.

Enhance Your Vitamin Intake with Balance Oil


Lykstad, J., & Sharma, S. (2023). Biochemistry, Water Soluble Vitamins. In StatPearls. StatPearls Publishing.

Forrest, K. Y., & Stuhldreher, W. L. (2011). Prevalence and correlates of vitamin D deficiency in US adults. Nutrition research (New York, N.Y.), 31(1), 48–54. https://doi.org/10.1016/j.nutres.2010.12.001

Traber M. G. (2014). Vitamin E inadequacy in humans: causes and consequences. Advances in nutrition (Bethesda, Md.), 5(5), 503–514. https://doi.org/10.3945/an.114.006254

Stevens S. L. (2021). Fat-Soluble Vitamins. The Nursing clinics of North America, 56(1), 33–45. https://doi.org/10.1016/j.cnur.2020.10.003

Asif, A., & Farooq, N. (2023). Vitamin D Toxicity. In StatPearls. StatPearls Publishing.

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