Our bodies can make four of 13 vitamins we need for optimal health. So actually, there are only nine vitamins that are essential.
Remember “essential?” We can only get an essential nutrient from our food. Regarding vitamins, Biotin (B7), Pantothenic acid (B5), and vitamin K are made in the human intestine, normally in amounts adequate to meet the body’s needs.
What is Vitamin based of?
The vitamin basics are first that they are organic molecules and all that means is that they contain a carbon atom.
Minerals, as opposed to vitamins, are not organic, they are stand alone atoms found in the periodic table of the elements.
The word “vitamin” is a combination of “vital” and “amine” having been coined by Casimir Funk way back in 1912. He was a Polish chemist and probably knows what he was talking about since he is credited with isolating vitamin B1, also known as thiamine, from rice. It is doubtful that they knew about essential vitamins versus the non-essential back then.
Vitamin D is obtained when sunlight hits our skin but usually not in sufficient quantities. The 400IU to 600IU’s of vitamin D we need must come from food such as milk or orange juice and supplementation.
I suppose we could say vitamin D is “sort of” one of the essential vitamins. There is a growing opinion among nutritionists that we probably need around 1200IU/day instead of the lower range.
How are the vitamins classified?
Vitamins are normally classified by their biological and chemical function instead of their structure. For example, there may be several chemical compounds that exhibit the same biologic activity associated with a specific vitamin. Whether they are essential vitamins or not has little to do with it.
So the letter name of a vitamin is just a generic description of a group of chemical compounds that have the same activity. The “A” in vitamin A, describes a retinal, a retinol and a several carotenoids.
As we see, vitamins have really complicated names; like A, B, C, D, E, and K.
Wait! That only adds up to 6, what happened to the other 7? Vitamin B is actually a collection of 8 separate vitamins, a complex, some of which we know better by their structural, or common, names:
- B1 you know as thiamine,
- B2 as riboflavin
- B3 as Niacin
- B5 as Pantothenic acid
- B6 as Pyridoxine
- B7 as biotin
- B9 as Folic Acid
- B12 as Cyanocobalamin (OK, so no one ever heard of cyanocobalamin)
Of the eight B vitamins, six are essential vitamins and two are made in our intestines.
Fat Soluble or Water Soluble Vitamins?
Water soluble vitamins dissolve in water and are excreted from the body fairly quickly which is why some people think taking vitamin supplements is a waste of money. Most of the vitamin goes down the toilet.
Nine of the 13 essential vitamins are water soluble so there is some truth to the “why take vitamins, you just pee them away” theory. Four vitamins are fat soluble which means that are absorbed in the intestine with the help of fats (lipids).
Sometimes we will see a vitamin product advertised as “energy vitamins”. Forget it! Vitamins don’t give us energy. I know, it’s a fine point but what vitamins do is control chemical processes in the body that convert food to energy and help the body use that energy.
What is Vitamin A good for?
Starting at the top, vitamin A is the first of the essential vitamins; fat soluble, and needed for vision and bone building. RDAs for male adults is 900 ug/day and 700 ug/day for females. Top dietary sources are liver, carrots, broccoli, sweet potatoes, kale, butter and spinach.
Remember mom telling us that eating carrots was good for our eyes? She was right; carrots have carotene which is a precursor to the essential vitamin A. Night blindness and possibly a dry cornea results from a deficiency.
There is an upper daily limit of between 2800 and 3000 ug and overdosing on vitamin A can have serious consequences including birth defects, liver problems, osteoporosis, and pressure on the brain causing headache, nausea, vomiting, tinnitis and double vision.
It would be hard to overdose on vitamin A in a normal diet but aggressive supplementation could cause problems.
What is Vitamin B good for?
All the B vitamins are water soluble and most play an important role in energy metabolism; the breakdown of glucose. All of them are essential vitamins except B5 and B7.
B1 we know as Thiamine and is needed for proper neural function and carbohydrate metabolism. Thiamine is somewhat delicate in that heat can decompose it and sulfites used in food preservatives can break its chemical bonds.
Common dietary sources are yeast, oatmeal, brown rice, whole grains, asparagus, kale and califlower. The RDA for Thiamin is 1.2 mg/day and beriberi is the result of a deficiency. This is a disease that mainly hit populations that depended on rice as a staple food, especially if the rice was “polished”. Symptoms include extreme fatigue, weakness, weight loss, emotional disturbances and irregular heart beat.
Mushrooms, besides being a mainstay of stir-fry and oriental food, are very rich in the B vitamins as well as the minerals, selenium, copper and potassium. They also contain a naturally occuring antioxidant as well as Beta-glucans, known to stimulate the immune system.
On the upside, there is no chance of an overdose with vitamin B1 since, being water soluble, any excess is excreted in urine or sweated out through the skin. Because of the latter, there are many people who swear that daily doses of thiamine are an effective mosquito repellent.
They recommend one or two 250 mg capsules per day. In his book, “Staying Healthy With Nutrition”, Dr. Elson Haas, M.D. writes that 50 to 100 mg a day is enough but then the University of Wisconsin says that no correlation between B1 and repelling mosquitos has been proven. Nevertheless, if you are a mosquito magnet, there’s nothing to lose in giving it a try.
What is Vitamin B2 good for?
B2 is Riboflavin, one of the essential vitamins, and is needed for many vital cellular processes. Good sources of B2 are eggs, milk, cheese, leafy greens, liver, mature soybeans, yeast and almonds. The RDA is 1.3 mg/day and there is no established upper limit. Riboflavin is sensitive to light and can be destroyed in bright light or sunlight.
If we get an excess of riboflavin, it is just excreted in urine. If you happen to have bright yellow urine, it’s probably because of an excess of B2 in your diet (or not drinking enough water).
A deficiency of B2 shows up as a sore, red throat, swelling of the mouth and throat mucus membranes, cancer of the esophagus in extreme cases, decreased red blood cell count and various skin lesions and disorders.
What is Vitamin B3 good for?
We know B3 as Niacin, another of the essential vitamins. It is important for repair of DNA, production of adrenal steroid hormones and cellular metabolism. It is widely available in meats, fish, dairy products, seeds, nuts and vegetables. The daily allowance is 16 mg/day with an upper limit of 35 mg/day.
Deficiency causes Pellagra which manifests itself as diarrhea, dementia, dermatitis and death; the four “D”s. Overdosing on B3 can result in liver damage.
What is Vitamin B5 good for?
Vitamin B5 is Pantothenic Acid and is one of the non-essential vitamins. It is required for metabolism and synthesis of carbohydrates, proteins and fats. Small quantities of B5 are found is almost every food with more amounts present in whole grain cereals, eggs, meats and legumes.
Its RDA is 5 mg/day for adult men and a little more for women. Deficiencies in pantothenic acid are extremely rare but can produce the sensation of “pins and needles” on the skin or of a limb being “asleep”. There is apparently no upper limit.
What is Vitamin B6 good for?
The vitamin B6, Pyridoxine, has numerous functions including metabolism of amino acids, synthesis of neurotransmitters, histamine and hemoglobin. It is a key member of the essential vitamins.
It also has a role in gene expression, the building of a protein or RNA from the information in a gene. It is widely available in most foods and especially prevalent in whole grains, meat, vegetables and nuts.
The RDA is 1.3 mg/day for both men and women. A deficiency in B6 produces anemia although deficiencies are not common. There is an upper limit of 100 mg/day above which, nerve damage can occur as well as an inability to sense the position of neighboring parts of the body.
What is Vitamin B7 good for?
Vitamin B7, Biotin, is another of the non-essential vitamins. If you see reference to a vitamin H, this is it. Biotin is necessary for the production of fatty acids and the metabolism of fats and amino acids.
The RDA is 30 ug(micrograms)/day and deficiencies are almost unheard of since intestinal bacteria usually produce an excess of the daily requirement. Natural food sources include eggs, meat, almonds and many others with the best being swiss chard, romaine lettuce, tomotoes and carrots.
What is Vitamin B9 good for?
Vitamin B9 is Folic Acid, also known as vitamin M and Folacin. It is essential for production and maintenance of new cells, synthesis of DNA, and evidence is suggesting that it can have a beneficial effect on stroke prevention and vascular health.
The RDA is 400 ug/day with an upper limit of 1000 ug/cay. The risk of taking too much B9 is low and the main concern is that exceeding the upper limit can mask a potential deficiency in vitamin B12. Leafy vegetables, beans, peas and fortified grain products are the chief sources of B9 in the U.S.
What is Vitamin B12 good for?
Vitamin B12, or Cyanocobalamin, is one of the essential vitamins that greatly impacts our health. It has a major role in the functioning of the brain and nervous system; is needed for the metabolism of every cell in the body; used in the formation of blood; and required for the synthesis of DNA, fatty acids and production of energy, just to name a few.
It is only available to us naturally from meat, shellfish, eggs and poultry. Thus, vegans and vegetarians should take care to supplement with B12. The RDA is 2.4 ug/day with no known toxicity or upper limit specified.
Deficiency of B12 can masquerade as many other conditions and the effects usually take years to manifest.
One very common result of a B12 deficiency is forgetfulness, mental fogginess, mood swings, apathy and depression which are often misinterpreted in the elderly as the onset of dementia or Alzheimer’s.
Lab tests for B12 deficiency can be inconclusive so it becomes very practical to merely supplement with vitamin B12 if the signs suggest a deficiency might exist. If the symptoms improve over time, that was likely the problem, especially if the person is elderly, poorly nourished or vegetarian.
It is non-toxic and inexpensive especially when compared to the cost of lab testing.
What is Vitamin C good for?
Vitamin C or Ascorbic acid or ascorbate, is one that most people are familiar with. It is an extremely effective antioxidant, protecting the body from the effects of free radicals (oxidative stress) and is a necessary cofactor for the biosynthesis of numerous biochemicals in the body. Vitamin C is one of the most essential of the essential vitamins.
A cofactor is a substance that needs to be present with an enzyme for a specific reaction to take place.
Natural sources of vitamin C are most fruits and vegetables especially oranges, limes and other citrus fruit. The RDA is the subject of ongoing debate but 90 mg/day is an accepted number with an upper limit of 2000 mg/day.
Scurvy is the result of a vitamin C deficiency which is the inability of the body to synthesize collagen, the protein of connective tissue. Scurvy was a sailors disease on the early sailing ships and was common during the U.S. civil war; both due to the lack of fresh fruit.
What is Vitamin D good for?
Vitamin D is one of the fat-soluble essential vitamins, vital to the maintenance of major organ systems.
Specifically, it regulates the levels of calcium and phosphorus levels in the blood by promoting their absorption from food in the intestines and also promotes the reabsorption of calcium in the kidneys.
In the immune system, it promotes phagocytosis, anti-tumor activity and modulation of the immune system. There is a huge and growing interest in vitamin D as a factor in the prevention and treatment of many catastrophic diseases, cancer being the focus of many studies.
Its RDA is 5 to 10 ug/day with a 50 ug/day upper limit. 1000 IU is very common in vitamin D supplements where 1000 IU equals 25 ug. Note that each vitamin has a different IU to ug conversion, so don’t apply the vitamin D conversion to other vitamins.
Current research indicates that the government RDA for vitamin D is extremely understated. It is now believed that adults require 5000 IU of vitamin D or even higher for prevention of many catastrophic diseases.
In supplementing vitamin D, one must be aware that there are two types; one being natural, the other synthetic.
D3, cholecalciferol, is the natural one and is the same vitamin D that our bodies make when exposed to the sun.
For more in-depth coverage of cholecalciferol, go to the separate page dedicated to vitamin D3.
D2, ergocalciferol, is synthetic. It has a shorter shelf life than D3 and is less effective than D3.
Many nutritionists and naturopaths go so far as to say that D2 should no longer be regarded as appropriate for supplementation nor for use in vitamin D fortified foods.
The most well known vitamin D deficiency disease is rickets, a softening of the bones in children. Natural sources are fatty fish such as salmon, tuna and others plus eggs and beef liver. Many cereals and dairy products are fortified with vitamin D but unfortunately it is almost always the synthetic D2.
One other important source of this vitamin is the sun. Certain ultraviolet rays will synthesize vitamin D in the skin in amounts depending on length of exposure, time of day and distance from the equator.
On a hot summer day in the direct sun, it is very possible to get 20,000 IU of vitamin D. Don’t worry about getting an overdose since there is a self correcting mechanism in the body that prevents it.
What is Vitamin E good for?
Vitamin E is a collective name for 8 fat-soluble compounds known as Tocopherols and Tocotrienols having great antioxidant properties. There are indications that it may act as a signaling molecule and protect neurons from damage. These two functions make “E” one of the essential vitamins we may want to supplement.
A number of foods provide vitamin E including nuts, seeds, vegetable oils, whole grain foods, milk and green, leafy vegetables. The RDA is 15 mg/day with 1000 mg/day as the upper limit. Deficiencies are rare and the result of an excessive intake is an increased risk of congestive heart failure.
What is Vitamin K good for?
Vitamin K, Menaquinone, is the last of the non-essential vitamins in that it is normally produced by bacteria in the intestines. It is fat-soluble, has an RDA of 120 ug/day with no upper limit determined. It is found in most leafy, green vegetables and some fruits.
It is needed in the synthesis of several proteins important to both coagulation and anti-coagulation. A deficiency could produce difficulty in the coagulation of blood and cause a susceptibility to bleeding.
If a vitamin is deficient or lacking in the diet, any reaction that uses that vitamin as a coenzyme cannot proceed. The result is the manifestation of a vitamin defcicency disease.