Traversing the Gut: How Water and Fat Solubilities Impact Absorption?

Did you know vitamins are absorbed differently? Some are stored in your body; others are flushed out.

And here's the caveat: how and where specific vitamins are absorbed can be equally important in avoiding a deficiency or going overboard. Because, while most aren't getting megadoses, if you eat a bowl of fortified cereal at breakfast, snack on an energy bar between meals, have a nice serving of enriched pasta for dinner, and take a nootropic to support your cognitive health, you could easily be over the recommended daily intake of a host of nutrients.*

What are water-soluble vitamins?

Water-soluble vitamins are a group of vitamins that dissolve in water and are not stored in the body. As a result, they are easily absorbed into the bloodstream and metabolized more quickly than fat-soluble vitamins.¹

Most vitamins are water-soluble:

• Vitamin C (Ascorbic acid)
• Vitamin B1 (Thiamine)
• Vitamin B2 (Riboflavin)
• Vitamin B3 (Niacin or Niacinamide)
• Vitamin B5 (Pantothenic acid)
• Vitamin B6 (Pyridoxine, Pyridoxal, and Pyridoxamine)
• Biotin (Vitamin B7)
• Folic acid (Folate, Vitamin B9)
• Vitamin B12 (Cobalamins)

Now, the fact that water-soluble vitamins are not stored in your body can be both an advantage and a disadvantage.

On the plus side, since your body eliminates excess water-soluble vitamins, you are far less likely to overdose on these vitamins. The downside is... you need to replenish them regularly through a balanced diet and/or supplementation to ensure optimal brain health and prevent deficiencies.*

And what's the deal with fat-soluble vitamins?

Unlike water-soluble vitamins, fat-soluble vitamins can only dissolve in fats and oils. These are absorbed along with fats you typically get from your diet and can be stored in the liver or fatty tissue for later use.

The benefit? You don't need to consume fat-soluble vitamins daily.

The downside? It may be possible to reach toxic levels of these vitamins. Luckily, while excessive intake of fat-soluble vitamins can be harmful, this is generally rare and associated with very high doses.*

The fat-soluble vitamins include:

• Vitamin A
• Vitamin D
• Vitamin E
• Vitamin K

Now, let's talk about the science of nutrient absorption.

Water-soluble vitamins are typically absorbed in the small intestine. There, tiny hair-like structures (called villi) found in the intestine's lining absorb these vitamins and transport them to the blood.

Now, you noticed how we said 'typically' instead of 'always'. That's because it's important to recognize the potential benefits of water-soluble vitamins when released in the stomach instead of the small intestine. We believe this preliminary phase may be pivotal in effectively absorbing and utilizing these vitamins, particularly vitamin B12.*

Vitamin B12 is a prime example of the intricate interplay between the stomach and the absorption process. Before B12 can be absorbed in the small intestine, it must first bind to a protein produced in the stomach called intrinsic factor (IF).^*2

How does this work? The stomach's acidic environment helps separate vitamin B12 from the protein it's attached to in food. Once separated, B12 combines with intrinsic factor, forming a complex - B12-IF. It's an important step because the small intestine can usually only absorb vitamin B12 when bound to intrinsic factor.^*3

Without this initial release and binding in the stomach, the vitamin B12 absorption rate in the small intestine may be hindered, leading to potential deficiencies. And a B12 deficiency isn't something you should tread lightly. If left untreated, it may lead to anemia, fatigue, weakness, constipation, and even nerve damage.^*4

Can I go overboard with too many vitamins?

Yes—especially if they're fat-soluble. But chances are, the unfortified foods you eat aren't a problem since it's pretty hard to overdo it from food alone.

So, you'll want to think about the nootropics you take and fortified foods or drinks.

Generally, if you're taking a nootropic, stick to one that's no more than the daily value for the fat soluble vitamins. (Daily value is the amount of a vitamin or nutrient that a person should get for optimum health.)^*5

Plus, when it comes to nootropics, you may also want to consider how the nutrients are delivered to ensure optimal absorption.

HCF®, for instance, often uses a capsule technology that combines Gellan Gum HPMC capsules and a time-release system designed to release water-soluble vitamins in the stomach and fat-soluble vitamins in the small intestine. This may offer better overall nutrient absorption and a more efficient use of essential nutrients than traditional capsules. It's quality over quantity.*