Categories: Vitamins

Water Soluble Vitamins – Part 1

vitamin C

We have covered many of the fat soluble vitamins in our two previous posts (part 1 and part 2), and now it is time to shift our focus to the second group of vitamins: those that are water soluble. Even though deficiencies in water soluble vitamins are less common than deficiencies in fat soluble vitamins, it is possible to not have enough of these important nutrients, which can cause all sorts of problems in the body (and you can of course also overdose with these vitamins, especially when supplementing without prior research or testing). Vitamin C is a nutrient everyone has heard of and we most commonly link it with fruits and vegetables like blueberries, oranges, and bell peppers in our minds, but there are things you might not really know about Vitamin C. Let’s cover it first, before diving into the whole extended family of B Vitamins, which deserve their own post.


Everyone knows Vitamin C. You might say that it is the popular kid among all of the vitamins, everyone likes it, everyone wants more of it, and many supplement brands on the market sell it. It can be found on boxes of fruit juice, fruit flavored candy, cereals, and sorbets. It seems like staying in bed and stuffing ourselves with The C is the best strategy for treating and preventing colds. As summer turns to fall, people seem to run into pharmacies and drug stores to get their tubs of fizzy Vitamin C dissolvable tablets to boost their immunity before cold season kicks in. And while it is true that Vitamin C is very important and useful, more doesn’t necessarily mean better. In this case, more is just more, and too much can also be a problem. And frankly, if your diet includes foods rich in Vitamin C, there is no need for daily supplementation for the average person.

Vitamin C, also known as ascorbic acid (since 1928) or ascorbate is a very powerful antioxidant that is able to control the damage caused by oxidative stress in the cells. But it doesn’t have only this one job. It is very important for collagen formation, thereby promoting healthy skin and joints. It also helps with iron absorption, as well as with effective use of this mineral (which is very important for blood health). Vitamin C also works as an antihistamine agent: it helps to manage swelling and inflammation caused by histamine during an allergic reaction. When your body is under a lot of stress or infection (both acute and chronic), Vitamin C stores are quickly depleted, which can cause deficiency and also have an impact on all of the functions described above. Without enough Vitamin C in the body, our skin and other tissues heal slower, anemia can develop as a result of poor iron absorption, allergic reactions tend to manifest themselves more severely, and immunity can become impaired. People with connective tissue disorders, mast cell activation disorders, or allergies may choose to supplement with therapeutic doses of Vitamin C for these reasons.

Is it true though that higher doses of Vitamin C can help us fight colds and prevent or shorten their length? This study showed that elevating the dose of Vitamin C doesn’t really have a significant impact on the symptoms of the common cold or its prevention. Another study even failed to show benefits for cancer patients compared to placebo, and there also isn’t strong evidence that supplementing with additional Vitamin C can solve any health problem without addressing the whole picture. It is merely a piece of a larger puzzle. Sébastien Noël from Paleo Leap sums it up by saying that “there is no strong evidence that Vitamin C is an effective treatment for anything but Vitamin C deficiency.” As we mentioned at the beginning, deficiencies in water soluble vitamins are not as common as deficiencies in fat soluble nutrients, which might suggest that most of us get enough through our diet. The small percentage of people who are deficient can actually benefit from adding more Vitamin C rich foods to their plate, without investing in supplements that might actually cause more harm than good when the dose is not adjusted for their bio-individual needs.

There are two very important things to say about Vitamin C in the body. First, because it is water soluble, it does not build up in our body, so we are not able to store it for later use (unlike fat soluble vitamins that we can store in our cells for future times of shortage, for example storing enough Vitamin Din summer to last well through the winter). Any Vitamin C we take in and don’t use that day will be excreted the same day, no storing. Boosting our immunity by very high doses of Vitamin C every day can have dangerous side effects, because our natural detox system has to deal with it in order to eliminate it later via urine, which can overburden our liver and kidneys. Very high doses of this nutrient can cause diarrhea, and some studies even showed that high levels of supplemental Vitamin C intake can contribute to kidney stones. As Noël points out, “Supplemental Vitamin C, like any other supplemental antioxidant, also has the paradoxical effect of reducing the body’s own antioxidant defenses. It’s basically training your body to rely on the supplement, instead of forcing it to do its own homework.”

The second thing we should mention is the fact that humans are one of the very few animals that can’t make their own Vitamin C, leaving us totally dependent on dietary sources. We learned that our bodies can manufacture Vitamin D from cholesterol or turn beta-carotene into Vitamin A, but there is no production line in our metabolism for Vitamin C. It might not seem logical at first, (why would we vitally need something we actually can’t manufacture? why would nature do this to us?) but our natural, healthy, real-food based eating automatically gives us adequate amounts of all of the important essential nutrients, including Vitamin C. The best plant based sources of Vitamin C are papayas, bell peppers (especially the yellow variety), kiwi, strawberries, blueberries, mangoes, broccoli, kale, and citrus fruit. Thyme is an excellent vitamin C source from the herb family, adding not just a boost of flavor to your dish, but some additional antioxidant properties. For the best absorption, it is ideal to consume fruits and vegetables when they are fresh and raw, as cooking can break down some of the vitamins.

The USDA recommendation for daily Vitamin C consumption is 75 mg per day for women and 90 mg per day for men, and the upper limit is 2 grams. The World Health Organization (WHO) offers completely different numbers – they only suggest around 45 mg per day. Some researchers even recommend adding up to 200 mg per day, which is still a number perfectly achievable through a real food based diet rich in colorful vegetables and fruits. If you focus on consuming enough plant based Vitamin C sources, you will automatically add plenty of other important nutrients to your diet, bringing your overall health to another level. Maybe this is why many studies see a correlation between high Vitamin C intake and overall health, but Vitamin C is not the only hero here. If you have difficulty accessing fresh fruits and vegetables, or if you struggle with significant allergies to many foods, it may also be worthy of considering supplementation. Also, considering the fact that produce today is very depleted compared to the fruits and vegetables our ancestors grew and ate, adding a high quality supplement (and dosing carefully) can minimize your worries.


There is not just one type of Vitamin B. Just as with the Vitamin K group, this family is bigger, and each member has its own specific role. In the next article we will get ourselves familiar with all of them, including Vitamin B2, known as riboflavin, an activator that helps all the other B Vitamins to do their job. Meanwhile, if you are interested in more Vitamin C facts, take a look at this great book: Vitamin C: The Real Story to learn more about the many health benefits, studies, and myths surrounding this nutrient. Stay tuned for more!

Author: Nina Vachkova