Tag: digestive disorders

Vitamins are important nutritional components. Vitamins are grouped into two categories fat soluble (vitamin A, D, E and K) and water soluble (vitamin B complex and C). Many component vitamins of vitamin B complex act as coenzymes during metabolic reactions example thiamine is the precursor of thiamine pyrophosphate (TPP), niacin is the precursor of nicotinamide adenine dinucleotide (NAD), riboflavin is the precursor of flavin adenine dinucleotide (FAD) etc. 

Vitamins are important for healthy living. They are required for normal body metabolism as many enzymes required coenzymes for their activity. The coenzymes are derived from vitamins. The vitamins are divided into two categories- fat soluble (vitamin A, D, E and K) and water soluble (vitamin B complex and C).

Almost all food is processed in some way before it is eaten. Commercially, the main reasons to process food are to eliminate micro-organisms (which may cause disease) and to extend shelf life. Simply cooking or combining a food with other foodstuffs to create a recipe is also considered a form of food processing. Whatever the case, the nutrient value of any food is often altered by the processing. Some vitamins are more stable (less affected by processing) than others. Water-soluble vitamins (B-group and C) are more unstable than fat-soluble vitamins (K, A, D and E) during food processing and storage. The most unstable vitamins include: folate, thiamine and vitamin C. More stable vitamins include: niacin (vitamin B3), vitamin K, vitamin D etc. So, maximum amount of vitamins are lost during food processing compared to carbohydrates, fats and proteins. 

Vitamins does not generate energy inside the body but are still essential.

Vitamins are essential compounds that must be acquired through the diet because the body can't synthesize them. One of the reasons vitamins are needed is because they play an indirect role in catalysis, in which enzymes speed up chemical reactions. However, most vitamins can't help enzymes on their own. In order to participate in catalytic reactions, most vitamins have to change into coenzymes that are small "co-pilot" molecules that pair up with enzymes. These coenzymes are extremely useful because they stay the same after catalysis, so they're recycled and reused multiple times.

Vitamins with some enzymes act as coenzyme. Coenzymes are organic molecules that are required by certain enzymes to carry out catalysis. They bind to the active site of the enzyme and participate in catalysis but are not considered substrates of the reaction.

Vitamin D is not one chemical but many. The natural type is produced in the skin from a universally present form of cholesterol, 7-dehydrocholesterol. Sunlight is the key: Its ultraviolet B (UVB) energy converts the precursor to vitamin D3. In contrast, most dietary supplements are manufactured by exposing a plant sterol to ultraviolet energy, thus producing vitamin D2. Because their function is almost identical, D2 and D3 are lumped together under the name vitamin D, but neither will function until the body works its magic. The sun’s energy turns a chemical in your skin into vitamin D3, which is carried to your liver and then your kidneys to transform it to active vitamin D. 

Biological assimilation, is the combination of two processes to supply cells with nutrients. The first is the process of absorbing vitamins, minerals, and other chemicals from food within the gastrointestinal tract. In humans this is done with a chemical breakdown (enzymes and acids) and physical breakdown. The second process of bio assimilation is the chemical alteration of substances in the bloodstream by the liver or cellular secretions. Although a few similar compounds can be absorbed in digestion bio assimilation, the bio-availability of many compounds is dictated by this second process since both the liver and cellular secretions can be very specific in their metabolic action. This second process is where the absorbed food reaches the cells via the liver.