Vitamin C enhance iron absorption

Ascorbic acid is a chemically defined compound, having the empirical formula C6HsO6 and a molecular weight of 176.13. Vitamin C is required for the biosynthesis of collagen, L-carnitine, and certain neurotransmitters; vitamin C is also involved in protein metabolism. A higher bioavailability of the dietary iron can be achieved by increasing the content of food components enhancing iron absorption.

Food iron is absorbed by the intestinal mucosa from two separate pools of heme and nonheme iron. Haem iron is found in animal foods such as red meat, chicken and fish. And non-haem iron is abundant in plant-based foods, including whole grains, beans, fruits and vegetables. Heme iron is absorbed with better efficiency from the intestine than nonheme iron.

The presence of ascorbic acid in the diet increases the absorption of nonheme iron. The dominant form of iron in foods is Fe3+, which is much less bioavailable than Fe2+. One of ascorbic acid's main attributes is its ability to reduce ferric to ferrous iron.

Ascorbic acid aids iron absorption by creating a chelate with ferric iron Fe3+ at a stomach acid pH that stays soluble at the alkaline pH of the duodenum, the first section of the small intestine.

In addition, ascorbate, ascorbic acid salt, donates an electron, acting as a free radical scavenger and reducing iron oxidation states to Fe2+, which is the only bioavailable form for enterocyte cells. Fe2+ is the only iron that can be absorbed through iron transporters of intestinal enterocyte cells.

In vivo observations showing an enhancement of iron absorption in the presence of ascorbic acid have been attributed to ascorbic acid's chelating and reducing properties. Reduction was previously thought to be an essential function of ascorbic acid prior to Fe2+ uptake by the divalent metal transporter (DMTl).

However, Fe3+ reduction has now been shown to be due to the action of ferrireductase Dcytb (duodenal cytochrome b) located at the brush border membrane of duodenal enterocytes. This suggests that ascorbic acid's main role is to promote iron solubility.

Four ounces (1/2 cup) of orange juice is enough to increase iron absorption. Other sources of vitamin C include citrus fruit, fresh bell peppers, strawberries, cantaloupe, and fresh broccoli.

Inadequate iron absorption leads to iron deficiency anemia. Iron deficiency is the most common nutritional deficiency worldwide.
Vitamin C enhance iron absorption

Vitamin C is an antioxidant

L-ascorbic acid, or vitamin C is a natural compound, whose peculiar antioxidant properties are used in biological systems and for the conservation of several different manufacts. Vitamin C (ascorbic acid) is a six-carbon lactone that is synthesized from glucose in the liver of most mammalian species, but not by humans, non-human primates, and guinea pigs.

Vitamin C is an antioxidant that helps protection against infection and iron absorption. It maintains prolyl hydroxylase in an active form by preserving its iron atom in the reduced Fe2+ state, and it keeps collagen in a sufficiently hydroxylated form preventing skin lesions and blood vessel fragility that are so prominent in scurvy.

When vitamin C is digested, it becomes a water-soluble antioxidant. Vitamin C is called an antioxidant because, by donating its electrons, it prevents other compounds from being oxidized. Vitamin C is one of the potent reducing agents and scavenger of free radicals in biological systems, working as a scavenger of oxidizing free radicals and harmful oxygen-derived species, such as hydroxyl radical, hydrogen peroxide (H2O2), and singlet oxygen.

Free radicals are molecules located in the body which are highly reactive, and known for causing tissue damage. Free radicals are made when human body breaks down food or when the body are exposed to tobacco smoke or radiation. The buildup of free radicals over time is largely responsible for the aging process. Free radicals may play a role in cancer, heart disease, and conditions like arthritis.

It is thought that a shortage of antioxidants could cause, or assist in causing, Alzheimer's disease, cancer, cardiovascular disease, cataracts, diabetes, hypertension, infertility, macular degeneration (eye lens degeneration), measles, mental illness, periodontal disease, respiratory tract infection, as well as rheumatoid arthritis.

Vitamin C is an antioxidant and natural rejuvenator and also helps the formation of collagen. Together with vitamin E make up a real beauty treatment for the skin.
Vitamin C is an antioxidant

Vitamin C in citrus fruit

Citrus is the largest genus in the family Rutaceae and is the most traded horticultural product in the world. Consumption of citrus fruits or their products is found to be inversely associated with several diseases. Citrus fruits and juices are rich sources of bioactive compounds, like flavonoids, carotenoids, limonoids, coumarin-related compounds, folates, essential oils, pectins and vitamin C.

Vitamin C, also is known as ascorbic acid contributes to many health benefits such as prevention of scurvy and cancer, relief from common cold, stimulate collagen synthesis and play a significant role in wound healing process.

Citrus is an excellent source of vitamin C. Most persons can achieve 100% of the RDA for vitamin C by consuming moderate amounts of citrus fruit.

Ascorbic acid acts as an antioxidant, a nutrient that chemically binds and neutralizes the tissue damaging effects of substances in the environment known as free radicals.

Reports show that vitamin C content in orange juices are between 29.0 and 82.5 mg/100 mL. Navel and Pineapple oranges have the highest contents of vitamin C, 82.5 and 78.0 mg/100 mL of juice, respectively.
Vitamin C in citrus fruit

Ascorbic acid molecule

Ascorbic acid also known as vitamin C is an important water-soluble vitamin essential for human life. Vitamin C or L-ascorbic acid is chemically defined as 2-oxo-L-theo-hexono-4-lactone-2,3-enediol.

It is a near planar five member ring with two chiral centers that resolves onto the four stereoisomers.

Ascorbic acid

It has a molecular mass of 176.12 g/mol, a density of 1.65 g/cm3, a very soluble in water (more than 30 g per 1 ml), and variably soluble in most-short-chain alcohols and glycols (1-5 g per 100 ml). Ascorbic acid can be reversely oxidized to semidehydro-L-ascorbic acid and further to dehyroascorbic acid.

Ascorbic acid is photosensitive and unstable in aqueous solution at room temperature. During storage of foods, vitamin C is inactivated by oxygen.
Ascorbic acid molecule

Ascorbic acid as food additive in food processing

Ascorbic acid (vitamin C) is a widely used food additive with many functional roles, many of which are based upon its oxidation –reduction properties.

It is the naturally occurring L-ascorbic acid. It is freely soluble in water and sparingly soluble in ethanol.

Its functional roles include its uses as a nutritional food additive, antioxidant, browning inhibitor, reducing agent, flavor stabilizer, modifier and enhancer, color stabilizer, dough modifier and many other capacities.

Vitamin C structure

Ascorbic acid is used as an antimicrobial and antioxidant in foods. It is preferentially oxidized in place of other substrates and complements very well as a synergist to other antioxidants, such as BHA and BHT in polyphase food systems.

Ascorbic and its sodium and calcium salts are used as nutritive additives. Whenever there is a need to preserve the vitamin content in fortified foods, the D isomer of ascorbic acid, isoascorbate or eyrthrobate, is incorporated with ascorbic acid.

Ascorbic acid is very widely used in bread making, where it is present as a ‘flour improver’. In practice, this means that the addition of ascorbic acid improves the bread texture and the size of the resulting loaf, the dough has greater elasticity, increased gas retention, and improved water absorption.
Ascorbic acid as food additive in food processing

Ascorbic acid in food

Ascorbic acid or vitamin C is required for the formation of the intercellular substances in the body, including dentine, cartilage, and the protein network of bone. Hence it is important in tooth formation, the healing of broken bones, and the healing of wounds.

It may be important to oxidation-reduction reactions in the body and to the production of certain hormones. Deficiency of vitamin C causes scurvy (spongy gums, loose teeth, swollen joints, hemorrhages in various tissue, etc) and impaired healing of wounds.

Orange juice is an excellent source of vitamin C. Tomato juice, if it has been processed properly, is a fair source of this vitamin. Green peppers, cabbage, broccoli, and Brussels sprouts are excellent to good sources of vitamin C, while other vegetables such as peas, spinach, and lettuce are good to fair sources. Many fruits contain fair amounts of ascorbic acid or vitamin C.

In 2007, scientists study shows that vitamin C is essential for plant growth. This discovery would have implications for agriculture and for the production of vitamin C dietary supplements. The discovery also identifies the new enzyme as a key player in controlling vitamin C accumulation in response to light.

The finding could pave the way for a new approach to producing vitamin C dietary supplementary. Vitamin C is currently produced by mixed fermentation and chemical synthesis. The new enzyme provides the potential to engineer microbes to produce vitamin C by a simpler one-step process.

In another study, a group of Johns Hopkins scientists have shown that vitamin C can indeed inhibit the growth of some tumors. They found that the antioxidants’ actual role may be to destabilize a tumors’ ability to grow under oxygen-starved conditions.

Since potential anticancer benefits of antioxidants have been the driving force for many clinical and preclinical studies, by uncovering the mechanisms behind antioxidants, scientists now better suited to maximize their therapeutic use.
Ascorbic acid in food

Ascorbic Acid

Ascorbic acid was recognized as early as 1734 as the factor in fresh fruit and vegetables that prevent the development of scurvy.

Vitamin C has been implicated in the hydroxylation of proline to form the hydroxyproline required in the formation of collagen.

It helps in the healing of wounds fractures, bruises and bleeding, gums and recues liability the infection.

Excellence sources of vitamin C are citrus fruits, berries, guava, capsicum and green leafy vegetables. Tomato juice, if it has been processed properly, is a fair source of this vitamin. Green peppers, cabbage, broccoli, and sprout are excellent to good sources of vitamin C.

Deficiency of vitamin C causes scurvy (spongy gums, loose teeth, swollen joints, hemorrhages in various tissue, etc) and impaired healing of wounds. Orange juice is an excellent source of vitamin C.
Ascorbic Acid

Absorption and Transport of Vitamin C in Human Body

Absorption and Transport of Vitamin C in Human Body
Humans are one of the few animals unable to synthesize ascorbic acid (vitamin C). Other primates, flying mammals, guinea pigs, and birds belonging to Order Passeriformes make up the additional animals to whom ascorbic acid is a vitamin.

Ascorbic acid (vitamin C) is synthesized from glucose. Animals that require an exogenous source of ascorbic acid are unable to synthesize gulonolactone oxidase, the last enzyme needed for the conversion of glucose to ascorbic acid.

The ascorbic acid contained in foods appears to be readily available and absorbed. Absorption of ascorbate occurs primarily via an active transport system, but simple diffusion may also contribute somewhat to uptake of the vitamin. Most of absorption occurs in the distal portion of the small intestine with degree of absorption decreasing with increased intake of the vitamin. Absorption rate can vary from 16% at very high intakes (approximately 12g) to 98% at low intakes (<20mg). But over a range of usual intakes from food (20 to 120mg/d), the average for overall absorption is around 90%.

The degree of absorption as suggested by the urinary excretion of the vitamin appears to be adversely affected by pectin, zinc, copper, and iron. At present it is unknown whether the decreased urinary ascorbic acid caused by the presence of the above three minerals reflects a less efficient absorption or an increased oxidation of the vitamin before it can be absorbed.

Absorbed ascorbic acid is transported in the plasma as a free anion, and it readily equilibrates with the body pool of the vitamin. The size of the pool therefore varies with the intake. Ascorbate moves freely into the cells, but the concentration is much greater in some tissues than in others. The highest concentration of the vitamin is found in the adrenal gland (30 to 40 mg/100g wet tissue), with the cortex having higher concentration than the medullar. Other tissues with particularly high concentration are the pituitary gland and the retina. An intermediate level of the vitamin is found in the liver, lungs, pancreas and leukocytes, while smaller amounts occur in the kidneys muscles and red blood cells. Tissue concentration of the vitamin usually exceeds the plasma level by three to ten times, the degree of concentration depending upon the specific tissue.
Absorption and Transport of Vitamin C in Human Body

Ascorbic Acid

Ascorbic Acid
Ascorbic acid or vitamin C is required for the formation of intercellular substance in the body, including dentine, cartilage, and the protein network of bone. Hence, it is important in tooth formation, the healing of broken bones, and the healing of the wounds. It may be important to oxidation-reduction reactions in the body and to the production of certain hormones.

Deficiency of vitamin C cause scurvy (spongy gums, loose teeth, swollen joints, hemorrhages in various tissues, etc.) and impaired healing of wounds. Orange juice is an excellent source of vitamin C. Tomato juice, if it has been processed properly, is a fair source of this vitamin. Green pepper, cabbage, broccoli, and Brussels sprouts are excellent to good sources of this vitamin C, while other vegetables such as peas, spinach, and lettuce are good to fair sources. Many fruits contain fair amounts of vitamin C.
Ascorbic Acid

Ascorbic acid function as antioxidant

Ascorbic acid function as antioxidant
L-ascorbic acid, its salts (sodium-L-ascorbic and calcium-L-ascorbate), and its isomers (D- and L-isoascorbic acid) are classified as generally recognized as safe substances by FDA. The L stereoisomer of ascorbic acid is the only from which carries significant vitamin activity. The vitamin activity of D-ascorbic is only one-tenth that of the L-form. The activity of D- and L-isoascorbic acid is only one twentieth that of L-ascorbic acid. FDA requires that label declaration if D-isoascorbic acid be made using the common name erythorbic acid to prevent potential misleading of consumers.

Ascorbic acid’s function in food systems is complex and depends on a number of factors. Its antioxidants activity is affected by the oxidation-reduction potential of the food system, time, PH, oxygen, trace metals, enzymes, other oxidants, and the concentration of the vitamin in comparison to the concentration of other reactants in the oxidation process. Other than bisulfites, ascorbic acids, its salt and its fatty acid ester (ascorbyl palmitate) are the only antioxidants permitted in foods which are capable of scavenging oxygen out of solution. Ascorbic acid is therefore, commonly used in canned or bottled products, particularly in beverages with headspace of air.

As an oxygen scavenger, ascorbic acid serves as a reducing agent. It transfers its hydrogen atoms to oxygen, making the oxygen unavailable for further reaction. In the process, the ascorbic acid is oxidized to dehydroascorbic acid, which in turn can function as an oxidizing agent by removing hydrogen from reducing agents such as sulfhydryl groups. Ascorbic acid and dehydroascorbic acid are thus reversible forms of vitamin C and both have physiological activity. Further, ascorbic acid may exert a chelating action, binding heavy chemical, if present will promote oxidation. When chelated with heavy metals, ascorbic acid loses its physiological vitamin activity.
Ascorbic acid function as antioxidant