Fat Soluble and Water Soluble Vitamins

Apr 27, 2021

 by Thomas Sampson


With summer winding down and winter coming, it’s time we start hearing everyone talk about vitamin D, and the importance of it. Today I wanted to take a second and go over some of the common vitamins, what they do and how much you really need to be taking.

Fat- and water-soluble vitamins

Vitamins can be broken into 2 major categories, fat soluble and water-soluble vitamins.

Fat soluble vitamins are vitamin A, Vitamin D, Vitamin E, and Vitamin K (potassium). This fat-soluble property allows them to be stored in the body in large amounts along with fat stores in the liver.

Fat soluble vitamins have been posted with a warning sign (especially vitamin A) as their levels can build up in the body and cause toxicity. Toxicity can lead to harmful effects although very few vitamin toxicity cases have been reported. This concern has increased in recent years due to the emerging use of supplements and the very popular occurrence of mega dosing vitamins to combat colds and other ailments. This is something to be aware of, although your levels of some vitamins may not reach a toxic level, too much can impair performance in athletes or anyone looking to improve their health and wellness.

Also, proper digestion of fat soluble vitamins requires the presence of fat in the diet. Think like this….if you are eating a salad, the dressing adds the unsaturated fat needed to digest the fiber from the salad greens. Adequate amount of fat in the diet is not normally a concern for someone focused on health and wellness because there is usually a good amount of fat in their diet. However, more competitive athletes may want to be conscious of their amount of fat as certain times of the year they may be on a lower fat diet.

I will not be going into very much science stuff today, focus is going over some vitamins, their functions and where they can be found.

Vitamin A – Its function in vision makes it one of the most well know vitamins. It also has some anti-oxidant properties, plays a roll in cellular growth, immune function, reproductive health, and the growth of hair, skin, and nails. Whole food sources for vitamin A are liver oils, egg yolks, whole milk, and dairy products, carrots, green leafy veggies, squash, sweet potatoes, and cantaloupes. A safe bet is to keep some of these foods in your daily intake to ensure proper intake of vitamin A.

Vitamin D – was originally revealed as the active nutrient in cod liver oil that was used to treat rickets. Later researchers also found that exposure to ultraviolet light cured rickets as well. We know that the body can produce vitamin D. Vitamin D has several important functions and is essential for growth and development. Its main function is the absorption of calcium and phosphorous to support the hardening of bones and teeth. In some studies, it has been shown to assist in muscle strength, reducing osteoporosis, and immune system function. Food sources are fish oils, eggs, butters, and many fish. Our bodies produce vitamin D when exposed to sunlight. Active people or anyone who lives in dark cold climates for half the year should be supplementing with vitamin D as our exposure to sunlight is limited for parts of the year and bone health is very important for everyone!!!

Vitamin E – is very popular for its role in reproductive health and enhancing sexual performance but has also been shown to play a huge roll in increasing athletic abilities due to its antioxidant activity and protecting the bodies cells from free radical damage. Food sources are vegetable oils, soybeans, corn, peanuts, safflower, nuts, meat, fish, animal fats, and fruits.

Vitamin K (potassium)– vitamin K plays a huge roll in blood clotting, bone tissue formation and metabolism. Vitamin K deficiency are rarely found in individuals eating a balanced diet high in fruits and veggies. However, deficiency can develop and there may be restrictions on green or purple colored vegetables. Some medication can inhibit the absorption of vitamin k (Tylenol). Food sources of vitamin D are green leafy veggies-some purple vegetables and small amounts can be found in milk, dairy products and fruits.

Water soluble vitamins

The water-soluble vitamins we will go over today are Vitamin c and the B-vitamins as they are some of the most commonly known and used. Water soluble vitamins are not normally stored in the body in any great amount so they need to be consumed regularly.

B- vitamins – Act as co-enzymes and are involved in the metabolism of carbohydrates, fats, and proteins. They play an important role in growth and development, tissue formation, and helping maintain the bodies ability to metabolize nutrients and use them. The B-vitamin family includes, Thiamin, Riboflavin, Niacin, Pyridoxine, Folate, B-12, and Biotin. The B-vitamins tend to work in tandem and food sources are animal products such as beef, fish, poultry, eggs, tofu, rice, banana, lima beans, peanuts, green veggies, and some grain products.

***B-vitamins are added to many cleanses and detoxes because they assist in metabolism of foods and nutrients giving people the sustained energy and boost, they feel from those products, leading many to believe those fads are working. When if one would eat a diet rich in B-vitamins and supplement with a B-complex if needed (which is much cheaper) they would feel better and their bodies would run more efficiently all the time.  When in all reality, the body has its own natural way of detoxifying. A marketed detox is likely just a marketing scheme. The best rule of thumb is to just listen to your body. Your body is usually giving you signs of what it needs and what it is missing.

Vitamin C – Scurvy is the disease that sailors and explorers experienced when they were deprived of fresh fruits and veggies for long periods of time. It has been known for a long time that eating lemons and oranges would prevent and reverse scurvy. It was discovered that those fruits contained vitamin C and it was in the 1930s that scientists isolated the vitamin and began producing it in supplement form. Vitamin C is essential to humans and can only be stored in the body in very small amounts. Vitamin C has many large roles in the body including, formation and maintenance of collagen, soft tissue and gum health, iron absorption, helps heal wounds, aids in metabolism and assists in immune function. Food sources, fruits (especially citrus fruits), green and red peppers, collard greens, broccoli, spinach, tomatoes, potatoes, and strawberries.

Key to vitamins

The main point of this is to show that with a diet high in fruits, veggies, and whole food sources for the most part vitamins will take care of themselves. There are some vitamins that almost everyone could benefit from supplementing with vitamin D especially in the winter months, but mostly we don’t have to worry about it if we are eating a well-balanced diet. There are some companies that offer blood tests to identity vitamin and mineral deficiencies which will give us clues about types of foods we should incorporate more of in our diets. Or vitamins we might want to supplement with. When it comes to eating a well versed and nutrient rich diet, the focus should be to eat as much REAL food as possible, if necessary, take a high quality vitamin supplement, and to listen to your body. Always follow dosage directions on labels and consult your doctor if you experience any side effects.


Thomas Sampson CFL-3, USAW-2, Sports Nutritionist

International sports science association. Sports nutrition. 5th edition. 2018 carpinteria CA

Nancy Clarks Sports Nutrition Guidebook. 4th edition. 2008 champaign IL