Vitamin C

Vitamin C is surely the most popular micronutrient out there. Supplements containing this vitamin were heavily advertised claiming that you will avoid getting sick or even fight the aging process because of its antioxidant capabilities. We’ll look later at how true these statements are. Vitamin C is also called ascorbic acid and it functions as an electron donor for 8 enzymes. Its role is complex and its most important functions are:

-          It aids in the synthesis of: carnitine (gets fat through cell membrane and is formed from lysine and methionine), collagen (structural protein which it is used in rebuilding tissue like wound healing), protein hormone production, and tyrosine(essential amino acid).

-          Supports better iron absorption from the GI tract. The iron from meat is better absorbed if taken with an orange or lemon juice.

-          As an antioxidant, in theory, reduces the damage from free radicals.

-          Helps the formation of cartilage, bone, and denton(tooth)

Sources:

¼ cantaloupe: 60 mg

½ cup grapefruit: 40mg

½ cup grapefruit juice: 35mg

½ cup cooked broccoli:60mg

1 cup sweet potatoes: 50 mg

1 kiwi: 75mg

1 lemon: 35mg

Recommended amount:

Healthy male, age 19-90: 90mg

Healthy female, age 19-90: 75mg.

Female smokers: 100mg

Male smokers 130mg

As you can see the recommended values can be easily reached. However some people need more. Depending on the amount of daily exercise, lifestyle choices, environment and others you can effectively use 500-1000mg/day. Current research show that amounts of 500mg-1500mg may protect against upper respiratory infections.

Excess vitamin C:

Relatively not toxic but it doesn’t mean it doesn’t have an effect. It’s possible to be linked with kidney stones. In the metabolism of vitamin C it results a urinary product called oxalate and many kidney stones are oxalate based. Another important aspect is that large amounts of vitamin C affect the bio-availability of vitamin B12 (remember the basic vitamin interactions). It can also cause chronic diarrhea.

It can affect results of certain health tests like glucose in urine. It can show that you have sugar in your urine when in fact it’s an excess of vitamin C. Although values a lot higher than the recommended dose can be beneficial, you should always stop at 2000 mg / day.

Vitamin C and common illness:

Everyone taking vitamin C as a supplement is doing it because they are convinced it will prevent illness. What do you think about this? True or false? A recent research done on a larger number of people than before had only one conclusion. Vitamin C can reduce the duration of the cold by 8% for adults 14% for children but it doesn’t prevent it, or reduce the intensity! So does this mean vitamins C is useless? No! As stated earlier vitamin C is a powerhouse and is essential for many internal functions. However it isn’t magical and it can’t be used to mend all your bad habits.

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Vitamin basics

When it comes to vitamins people have extremely different opinions. Some think that they aren’t necessary and that you can live just fine with what you get from food, while others tend to exaggerate and think of them as all around “fixers”. As in most cases the truth is somewhere in the middle. Vitamins are organic substances, meaning they are carbon based. They don’t have any calories although I’m sure you’ve heard people complain that they have gained weight after taking a complex of vitamins (we’ll tackle ridiculous myths like this one in future articles). Vitamins can’t be produced internally so your body must get them from food or supplements. Exception to this rule is vitamin D.

            There are about 13 different vitamins which can be classified in 2 categories:

-          Fat soluble. They are dissolved and remain in the body’s fat store. Because of this, their need on a day to day basis is a little lower. Excess of these vitamins are usually toxic. You might find on a nutrition label, next to vitamin A part of it in the form of beta-Carotene just because of this possible toxicity (beta-Carotene is a precursor). These vitamins are:

o       Vitamin A

o       Vitamin D

o       Vitamin E

o       Vitamin K

-          Water soluble. They are not stored in your body and must be replaced each day. Although they are lost in urine it doesn’t mean they can’t have side effects. Too much of a good thing is not always that good. They act as co-enzymes (they combine with a larger compound to form enzymes) and thus help you use your metabolic machine a little bit better. There some exceptions to the rules here as well. Although it’s a water soluble vitamin, B6 can be toxic for you in large quantities and B12 can actually be stored in the liver for long periods of time. These vitamins are:

o       Vitamin C (ascorbic acid)

o       Vitamin B1 (thiamin)

o       Vitamin B2 (riboflavin)

o       Vitamin B6 (pyridoxine)

o       Niacin (nicotinic acid)

o       Pantothenic acid

o       Biotin

o       Folic acid (folacin or folate)

o       Vitamin B12 (cobalamin)

If you’re having less than 40-50% of daily recommended values of these vitamins signs of deficiency can be seen after only 4 weeks. A term which you should always consider when talking about vitamins is bio-availability, because it shows how much of these substances are actually absorbed. This is important because people usually think of vitamins as a singular compound. In fact they are found in many different forms, not all having the same effectiveness. For example vitamin E can be found in 8 such molecular forms. Bio-availability is also affected by other food components. For example most of the vitamins are better absorbed if taken with a meal but folic acid is recommended on an empty stomach. The absorption of iron is stimulated in the presence of vitamin C and so on… in general there are all dependent on “shared variables” which means that a gain in one can be a loss for another.

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