You know that you need vitamins. This guide will tell you which vitamins there are, what happens when you have to little or too much of them, how much of each you need and where they can be found.
Fat-Soluble Vs. Water-Soluble
One very important distintion we have to make is between vitamins that are soluble in fat and those soluble in water.
The former (A, D, E, K) can accumulate in the body and, when a sufficient amount is reached, become toxic. An overdose of vitamin A, for example, can lead to liver damage, osteoporosis (brittling of the bones), birth defects and others. Except for megadoses taken at once, excess amounts of water-soluble vitamins ingested over longer stretches of time are simply expelled with the urine.
Natural Vs. Synthetic
For ease of use, many people like to use multivitamin tablets to cover their daily needs. However, in many of these, some of the vitamins are artificially produced and at least synthetic vitamin E may not work as well at its natural counterpart. You should therefore at least make sure that your product contains natural vitamin E.
To tell the synthetic from the natural version have a look at the bottle or package: Natural vitamin E will be stated as “d-alpha tocopherol”, “d-alpha tocopherol acetate” or “d-alpha tocopherol succinate”. The synthetic version will be labeled with a “dl-” instead of the single “d-“.
Vitamins From Food Or Tablets?
I elaborately covered the possible downsides of vitamin supplementation in an article. In short, food sources are preferrable, because food not only contains vitamins, but also phytonutrients that may flank the effectiveness of vitamins.
In the leftmost column you find the name of the vitamin, “F / W” indicates if it is fat- or water-soluble (“F” stands for “fat-soluble”, “W” stands for “water-soluble”). “RDA” is the “recommended daily allowance”, based on an average adult. The amounts are in “µg” (microgram, 1/1000 milligram), and “mg” (milligram, 1/1000 gram).
The “Sources” give you some examples for foods the vitamin naturally occurs in, while the “Deficiency” and “Overdose” columns show you the most closely associated examples for a lack or overabundance of a given vitamin.
|Vitamin||F / W||RDA||Natural Sources||Deficiency Symptoms||Overdose Symptoms|
|A||F||800 µg||Liver, dandelion greens, carrots, broccoli leaves, sweet potatoes, butter, kale, spinach, pumpkins||Night blindness, limited function of immune system||Liver problems, birth defects, osteoporosis, skin discoloration, hair loss, dry skin|
|B1||W||1.2 mg||Whole wheat, pork||Beriberi, Wernicke-Korsakoff-Syndrome||Muscle relaxation, drowsiness|
|B2||W||1.3 mg||Milk, eggs, liver, kidney, yeast extract||Ariboflavinosis||–|
|B3||W||16 mg||Nuts, eggs, salmon, liver, heart, kidney, chicken, beef||Pellagra||Liver problems|
|B5||W||5 mg||Meat, whole grains, broccoli, avocados||Paresthesia||Diarrhea|
|B6||W||1.5 mg||Whole grains, nuts, bananas||Anemia, peripheral neuropathy||Nerve damage|
|B7 (or H)||W||30 µg||Egg yolks, peanuts, liver||Dermatitis, enteritis||–|
|B9||W||400 µg||Spinach, asparagus, beans, peas, lentils, liver, kidney||Birth defects||Can mask the effect of B12 deficiency (see below)|
|B12||W||2.4 µg||Fish, meat, liver, most milk products||Anemia||Acne-like rashes|
|C||W||90 mg||Papaya, strawberries, lemons, kiwifruit, broccoli||Scurvy||Diarrhea, kidney stones|
|D||F||15 µg||Fish, whole eggs, beef liver||Rickets, osteomalacia||Vomiting, dehydration, fatigue, constipation, muscular weakness, decreased appetite|
|E||F||15 mg||Nuts, lettuce, spinach, tomatoes, asparagus, papaya, broccoli||Anemia in newborn babies||Possibly heart failure|
|K||F||120 µg||Green vegetables, avocado, parsley, kiwifruit, grapes||Bleeding diathesis||Increased coagulation|
Picture courtesy of United States Department of Agriculture.