The structure of vitamins and minerals is quite different as well as the amounts present in the foods that we eat. They can be tightly encased inside food aggregates; they can appear in a free form; or as compound bonds to large molecules.
Usually they are liberated by the grinding process during eating. The breaking down of starch and proteins also liberates them.
The body requires these nutrients in specific amounts. The body takes these nutrients in very specific ways. This is because they have active transport in the place for absorption. This active transport picks a vitamin or mineral and takes it through the intestinal cell wall where it is released directly or transferred to a different transport molecule.
Vitamins and minerals are usually smaller and in lower levels than carbohydrates, amino acids, fats, etc. Thus the active transport, which requires energy to function normally, has to select and pull them out of food and hence take them to the body.
Examples of minerals taken into the body through active transports are iron and calcium. Water soluble vitamins such as Vitamin A, D, K and E are also carried via this transport. The active transport is found in the jejunum – the middle section of small intestines.
Calcium and iron are minerals that are absorbed either at the first part of small intestine or at the jejunum. The water soluble vitamins are absorbed with fat miscelles. Thus their full absorption requires fats.
Magnesium is very important for energy production, bone health and the general functioning of the body because it activates over 300 cellular enzymes. A constant supply of magnesium is vital for the optimal functioning of the body.
The body depends totally on dietary intakes of this mineral. Its absorption requires a healthy intestinal lining. Magnesium can be absorbed through any section of the small intestine and also in the colon.
If you do not get enough magnesium from foods, or your intestinal truck has a low ability to absorb this mineral due to intestinal inflammation or disease, then this results to various health problems including depression, weak bones, muscle twitching or tremors, irritation and restlessness and weakness.
Whole foods like grains are highly rich in magnesium. However these high levels are removed by grain processing. This is why whole grain bread and cereals have higher amounts of this mineral than white bread, because the latter comes from refined flour.
The absorption of this vitamin is different from other vitamins and minerals. Vitamin B12 is usually attached in proteins and thus it is liberated though protein breakdown. The absorption of this vitamin requires intrinsic factor – a protein that is made in the starch. But its absorption does not take place until when the vitamin B12 intrinsic factor complex get to the ileum – the final part of small intestine.
The level of vitamin B12 digestion depends on the amount of stomach acids that your body produces. This is because this vitamin attaches itself to protein whose breakdown requires stomach acid. Research studies also shown that the secretion of intrinsic factor is low when the stomach acid is low.