Vitamin C - Heart disease

Home > Vitamin C and heart disease

Vitamin C as an antioxidant and contributor in collagen synthesis, has very crucial role in prevention and treatment of heart disease.

Clinical prevention of scurvy disease can be achieved with daily intake of about 100 gm of vitamin C.
But the nutritional requirement of ascorbic acid is much higher than this for warding off adverse health conditions, especially the ischemic heart disease.
subclinical form of vitamin C deficiency exists in many people leading to diseases like cardiac disease, strokes, diabetes etc.

Vitamin C - heart disease and arterial walls

As the heart pumps blood back to the body all the blood vessels experience pressure, especially arteries.
When the blood vessels are healthy, normal blood flow is maintained.
If the arteries are weak, constricted or have deposits in the wall, there is cardiac stress and diseases like hypertension, cardiovascular disease is caused.

Collagen is found in the artery wall and is necessary for the elasticity and tenor of the artery.
Ascorbic acid is necessary for collagen synthesis.
When there is deficiency of vitamin C, the artery walls harden and develop minute cracks and blood leaks into the surrounding tissues.
A focal point inflammatory, disease and infection is formed.
This leads to production of prostaglandin thromboxane.

In order to plug these leaking cracks platelets aggregate and lipoproteins are deposited.

The LDL cholesterol in the blood forms further deposits at this point and a plaque is formed.

This leads to narrowing of the blood vessels and to keep up circulation the heart has to pump harder.

Fresh cracks get formed due to pressure and a chain reaction starts leading to further narrowed vessels.

The consumption of ascorbic acid makes the endothelial lining of the artery wall healthy and elastic by proper and sufficient deposits of collagen.

Further ascorbic acid can prevent the plaque formation. Ascorbic acid inhibits the oxidative modification of LDL (low density lipoproteins) and prevents deposits.

Ascorbic acid hinders blood platelets aggregation and the formation of clot.

Ascorbic acid increases the fibrinolytic activity and the dissolution of plaques.

Ascorbic acid restores the characteristics of atherosclerotic arteries back to normalcy by dilation and restores proper blood supply curing cardiac disease.

It is vital for the healthy heart and for protection from cardiac conditions.

Related topics:
Ascorbic acid functions
Health benefits
Vitamin C and Liver
Kidney

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Vitamin C in collagen synthesis

Home › Nutritional deficiency › Vitamin C - Collagen synthesis

Vitamin C (ascorbic acid) is required for collagen synthesis, a vital protein component of connective tissue.

Collagen is a unique type of protein required by almost all organs of the body and the synthesis of which depends on vitamin C availability. It is the abundant protein in the human body, makes up to 30% of its protein content. In the skin 75% of the dermis is made up of it. Vitamin C plays an important role as cofactor in its formation. There is synthesis of 29 of its types identified so far in the body. Out of these four are main types making up 90% of the body connective tissue.

Type 1: This is for the formation of skin, organs, bone matrix, ligaments, tendons and blood vessels.
Type 2: This is for the formation of cartilage.
Type 3: This is for the formation of the reticular fibres.
Type 4: This is for the formation of Cell basement membrane.
Type 5: this is for the formation of Cell surfaces, placenta and hair.
Vitamin C deficiency affects the assembly, secretion, or other biological processes involved in the production of this vital protein.

Vitamin C in Collagen synthesis

Collagen has unique amino acid composition depending upon the type of tissue formed. Amino acid Glycine (Gly) is found at almost every third place and amino acids Proline (Pro) and its derivative Hydroxyproline makes up about 10% of this protein. Proline and hydroxyproline play key role in the stability of this protein by helping the twist of helix.

In the higher organisms like humans, for maintaining the connective tissue, critical and crucial biochemical process is hydroxylation of proline.
Its synthesis for increasing its conformational stability significantly, hydroxylation of the amino acid proline by the enzyme prolyl hydroxylase is required.
Ascorbic acid is a necessary cofactor in this biochemical process.

Vitamin C (ascorbic acid) and enzyme catalysed reactions occurs in the lumen present in the endoplasmic reticulum.
Lack of this ascorbic acid (ascorbate) cofactor results in defects in this hydroxylation and mutations in the enzyme prolyl hydroxylase affecting the protein and its proper formation.
Vitamin C in collagen synthesis process more than serving as catalyst gets destroyed by donating H atom in the critical process of assembling this protein in the tissues.

Related topics:
Vitamin C (ascorbic acid)
Foods - Sources
Vitamin C in nutrition
Deficiency and Therapy
Antioxidant

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Vitamin C (ascorbic acid) - properties - synthesis - production

Home › Nutritional deficiency › Vitamin C (ascorbic acid)

Ascorbic acid (vitamin C) is an essential organic compound required for umpteen biosynthetic activities in most of the animals and all humans.

Properties of vitamin C
Ascorbic acid, the official name of vitamin C, was first discovered in 1912.
In 1933 it was isolated for the first time in lemons.
It appears as white or light yellow crystals or powder. Its empirical formula is C₆H₈O₆.

It is made up of elements carbon, hydrogen and oxygen.
It is water soluble. In alcohol it dissolves sparingly.
In benzene, ether and chloroform it is insoluble.
It is also known as L-ascorbate. Its chemical name is L-ascorbic acid.
At the temperature of 190-192 degree Celsius it decomposes.

Its bioavailability is rapid and complete. It binds negligibly with proteins.
Its metabolic half life is 30 minutes. It is excreted by the kidneys.
 Biosynthesis of vitamin C in animals and the human inability
It is biosynthesized by reptiles and birds (older orders) in their kidneys. Birds of recent orders and most of the mammals synthesize it in their livers.

In these animals glucose is converted into ascorbic acid with the help of the enzyme L-gulonolactone oxidase.
In most of these animals ascorbic acid is a natural metabolite of liver.
Humans, most of the primates and guinea pigs cannot produce vitamin C in the body and they are required to source it from their food and can develop its deficiency.

It is hypothesized that humans and primates, by a genetic mutation, must have lost their capacity to synthesize L-gulonolactone oxidase long ago due to which they are unable to produce ascorbic acid.
This being a vital nutrient for the biosynthetic activities, is included as 'vitamin C' among essential nutrients.
The pharmacophore (the molecular frame required for the biological activity) of ascorbic acid to function in the biological activities is ascorbate ion.
L-ascorbate, which is related to glucose in structure, occurs naturally attached to hydrogen forming ascorbic acid.
Alternatively it may occur attached to metal ion forming its ascorbate.
This ascorbate ion is highly reactive and scavenging free radicals, functions as antioxidant.
 Absorption, transport and excretion of ascorbic acid
Vitamin C is absorbed into the body by simple diffusion and active transport by SVCTS (Sodium-Ascorbate Co-Transporters) and GLUTS (Hexose transporters).
In normal regular intake absorption is 75-90%.
In heavy doses the absorption rate may fall down to 15%.
There is a renal reabsorption threshold and any concentration above this is excreted through urine.
Though there is a blood threshold for renal reabsorption, many tissues in the body maintain higher concentrations of it.
Adrenal glands, pituitary gland, corpus luteum, thymus and retina accumulate vitamin C as high as 100 times the concentration in blood.
The excess of vitamin C which is not yet excreted is oxidised and broken down by the body by the activity of the enzyme L-ascorbate oxidase.

Commercial production of Ascorbic acid
Earlier vitamin C has been made commercially by extracting it from plants.
Later vitamin C was chemically synthesized. Presently it is being made by two processes.

Reichstein process
In the Reichstein process, which is traditional and earlier, glucose is converted into sorbitol by heat treatment.
Sorbitol is fermented and oxidised (by a microorganism) to form sorbose.
This is made to react with acetone to produce di-acetone sorbose and further oxidised to produce DAKS (di-acetone keto gulonic acid).
Then by dissolving it in a mixture organic solvents the structure of DAKS is rearranged with the help of a catalyst to form vitamin C.
In the next step, by recrystallization vitamin C is purified.

Glucose by heat treatment --> Sorbitol by fermentation --> sorbose by chemical process --> Diacetone sorbose by chemical process --> DAKS by chemical process --> raw vitamin C by recrystallisation --> purified vitamin C

two-step fermentation process

In the two stage fermentation process developed in China, a second stage fermentation of sorbose produces KGA and this like DAKS by the same chemical process is converted into crude vitamin C and then purified.

The later process is cost effective and more realisation of ascorbic acid is achieved.
Much of the world supplies of vitamin C are from China. glucose by heat treatment --> sorbitol by fermentation --> sorbose by fermentation --> KGA by chemical process --> raw vitamin C by recrystallisation --> purified vitamin C

Other uses of ascorbic acid
Calcium, potassium and sodium salts of ascorbic acid are used as food additives for their antioxidant properties.
Ascorbyl stearate or ascorbyl palmitate, which are fat soluble esters of ascorbic acid, are used for protecting fatty food from oxidation.
It is used for enhancing the fermentation process in food preparation. It is also used in chemical processes as reducing agent. Vitamin C (ascorbic acid) is used to fix and keep the red colour of meat products.

Related topics:
Vitamin C Functions
Benefits
Too much - Over dose
Vitamin C toxicity
Side effects
Foods - Sources

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Properties of vitamin C and its production and synthesis.

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Function of vitamin C in human physiology

Home > Functions of vitamin C

Function of vitamin C in our body includes many vital metabolic activities like protein synthesis, energy production, antioxidative actions and neurotransmission.

Vitamin C being a very essential nutrient has important functions almost in all systems of the body. Some of the functions are briefly listed.

Function of vitamin C in the enzymatic reactions for collagen production

Vitamin C acts as an electron donor in many different enzymatic reactions taking place in various organs of our body.

It is a co-factor in lysyl hydroxylase and prolyl hydroxylase, the enzymes essential for collagen hydroxylation.

This hydroxylation of collagen is essential for its role in the developing and maintaining cartilage, blood vessels and scar tissue.

The function of vitamin C in energy production

The role of ascorbic acid in the enzymatic reactions for the production of carnitine is crucial.

Carnitine is biosynthesized from amino acid methionine and amino acid lysine.

Carnitine is required for transporting fatty acids from cytosol or intracellular fluid into mitochondria, (powerhouse of the cell) for the generation ATP and metabolic energy by the breakdown of lipids.

The role of vitamin C in neuro-transmission

The role of ascorbic acid in the enzymatic reaction of dopamine beta hydroxylase is in the biosynthesis of stress hormone norepinephrine (also a neurotransmitter) from dopamine.

This hormone along with epinephrine (another hormone and neurotransmitter) induces the brain for flight-fight response.

In another enzymatic reaction the role of ascorbic acid is in regulation of tyrosine (an amino acid) metabolism.

Tyrosine is a precursor of dopamine which in turn is a precursor for neurotransmitters.

The function of vitamin C in hormone production

In another enzymatic reaction with the association of ascorbic acid, amide groups are added to peptide hormones to increase their stability.

Some of the peptide hormones like luteinizing hormone, follicle-stimulating hormone, prolactin, adrenocorticotropic hormone (ACTH), growth hormone and antidiuretic hormone are very important for reproductive health, excretory organs, hormone production and regulation.

Vitamin C in immune reactions

One of the important role of vitamin c is in the production of certain antibodies essential for neutralising proteins of pathogens and give faster recovery from diseases.

Ascorbic acid helps in the production of interferon which gives resistance to the body for countering viral attacks.

Ascorbic acid counters the allergic reactions by interfering in the release of histamines and reducing histamine levels in blood circulation.

Nitrosamines are potential carcinogenic compounds. They are produced from nitrites found in food. These can cause cancer in the digestive system and their formation is blocked by vitamin C in the stomach.

Function of vitamin C in nutrition

Folic acid has to be converted into active form for proper utilisation and ascorbic acid aids in this metabolism of folic acid.

Iron has to be in oxidized form for absorption and utilisation by the body and in the presence of vitamin C this is achieved.

Vitamin E is regenerated from its reduced form by ascorbic acid.

Ascorbic acid functions as a regulator of serum levels of copper, iron and lead keeping them below toxic levels by stimulating their excretion, decreasing their absorption or increasing their absorption as required.

Function of vitamin C as antioxidant

The antioxidant activity of ascorbic acid prevents the oxidation of LDL (low density lipoprotein), oxidative damage of DNA and proteins.

Related topics:
Vitamin C (ascorbic acid)
Benefits
Too much - Over dose
Toxicity
Side effects
Foods - Sources

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Vitamin C - ascorbic acid - health benefits - uses

Home › Nutritional deficiency › Health benefits and uses of ascorbic acid

The benefits and uses of vitamin C in the maintenance of the healthy body are numerous.

One of the very important uses and health benefits of vitamin C is its function as a potent antioxidant.

Vitamin C health benefits and uses as antioxidant
Our body's metabolic reactions and energy production causes free radicals to be produced.
These free radicals, though have their requirement for our health, in excess, cause oxidative damages to our body cells and their death.
Ascorbic acid is a potent antioxidant and it neutralizes the free radicals and saves our body and health from these damages.

Health benefits and uses in the treatment and prevention of scurvy disease
Scurvy is a debilitating and life threatening disease caused by the deficiency of ascorbic acid.
100-120 mg of ascorbic acid is the daily requirement to ward off scurvy and improve health.
Daily consumption of citrus fruits keeps this disease at bay.

Vitamin C health benefits and uses in collagen production and wound healing
Collagen is a body connective tissue and fiber found in various parts of the body.
As connective tissue beneath the skin, it gives the skin elasticity.
Vitamin C forms the matrix for the calcium and phosphate deposition and the formation of bone tissue.
It is also required for connecting bones, cartilages and the tendons.
Collagen has important role in wound healing. For the formation of collagen ascorbic acid is very essential.

Health benefits and uses in cellular immune functions and in enhancing immunity
Vitamin c influences the immune system and helps in its fight against bacteria, viruses and other pathogens.
It is shown to stimulate production and function of white blood corpuscles (leukocytes).
It is also found to increase the production of antibodies.
It can also control the production of histamine and allergy.

Vitamin C health benefits and uses during the treatment of diseases and in their prevention
Coronary heart disease: regular dietary intake has been proved to decrease the risk of coronary heart disease.

Cardiovascular disease: as ascorbic acid is vasodilatory in function the incidence of cardiovascular diseases has been greatly reduced with the regular vitamin C intake.

Hypertension: regular supplementation with ascorbic acid reduces hypertension.

Stroke: it has been found that in persons with higher levels of serum vitamin C the risk of stroke is greatly reduced.

Cancer: there is marked improvement in the health of cancer patients with higher vitamin C intake and also protection to the users from cancer of gastrointestinal system and respiratory system.

Cataracts: The levels of vitamin C in the eye lens is found to decrease with age. Regular consumption of vitamin C reduces the risk of cataract.

Gout: Studies have shown that higher serum levels of uric acid causes gout. With regular consumption of vitamin C the serum levels of uric acid gets reduced.

Diabetes: regular intake of vitamin C, reduces the cardiovascular disease in the diabetes patients.

Vitamin C benefits and uses in medication and side effects
There is an increase in the requirement of vitamin C during the medication with antibiotics.

Benefits and uses in hormone production and body metabolism
Vitamin C helps in the production of hormones like thyroid.
Vitamin C regulates the adrenal glands and the production of stress hormones epinephrine and norepinephrine.
One of the health benefits and uses is in the metabolism of tryptophan, tyrosine and folates.

Benefits and uses for smokers, alcoholics, obese persons and workers in toxic environment
The body systems of alcoholics, smokers and persons living in toxic environment are always under stress. Their bodies utilizes more ascorbic acid to counter the stress.
Regular supplementation improves the health and benefits and protects them from faster deterioration of their conditions.

Uses in skin care, wrinkles and ageing
Skin aging and wrinkle formation are associated with oxidative activities due to exposure to elements (especially sun) and food habits.
It has been clinically proved that ascorbic acid slows the aging process.

Vitamin C health benefits and uses in the absorption of essential minerals and protection from harmful elements
For the absorption and use of iron in the human body ascorbic acid is very essential.
To tide over the ill effects of toxins like DDT and the heavy metals like mercury, cadmium and lead higher quantities of vitamin C is required.

Related topics:
Vitamin C (ascorbic acid)
Functions
Too much - Over dose
Vitamin C toxicity
Side effects
Foods - Sources

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Vitamin C - Food sources

Home > Food sources of vitamin C

A wide variety of sources of vitamin C foods are available from plant and animal origins.

Vitamin C from plant origin

A number of fruits like papayas, lemons, oranges, pineapples etc.. contain considerable amounts of ascorbic acid and are great natural resources.
Vegetables and leafy vegetables like red and green peppers, cauliflower, cabbage, broccoli, parsley and peas are some of the good sources.
Some of the fruits and vegetables and the available amount of ascorbic acid in 100 gms is listed below.
Richest of vitamin C foods:

Plants	Amount (mg / 100g)
Kakadu plums	3000
Camu Camu	2800
Rose hip	2000
Acerola	1500
Seabuckthorn	700
Jujube	500
Indian gooseberry	450
Baobab	400

Richest source of vitamin C - Kakadu plum
Vitamin C from fruits:

fruits	Amount (mg / 100g)
Blackcurrant	200
Guava	100
Kiwifruit	90
Redcurrant	80
Lychee	70
Papaya	60-70
Strawberry	60-65
Orange	50-55
Lemon	40
Melon	40
Grapefruit	30
Raspberry	30
Tangerine	30
Mandarin orange	30
Passion fruit	30
Lime	30
Mango	28
Blackberry	21
Melon	20
Blueberry	10
Pineapple	10
Grape	10
Apricot	10
Plum	10
Watermelon	10
Banana	9
Avocado	8

Vitamin C from vegetables:

vegetables	Amount (mg / 100g)
Red pepper	190
Parsley	130
Broccoli	90
Brussels sprouts	80
Cauliflower	40
Garlic	31
Spinach	30
Cabbage	30
Potato	20
Tomato	10
Carrot	9

Among the animal sources of ascorbic acid foods, livers of live stock, oysters, cod roe and milk are important.
Great care is required in processing and storing of the vitamin C foods to reduce storage losses.
We should reduce the exposure of the vegetables to sunlight and air.
Freeze-drying of the fruits and vegetables reduces the losses.
Microwave cooking preserves much of the ascorbic acid present in vegetables.
We should cook in minimal water and cut the vegetable into bigger pieces to avoid losses.

Recommended daily dietary allowance of ascorbic acid:

age group	requirement in milligrams
0-6 months	40
7-12 months	50
1-5 years	20
5-10 years	25
10-18 years	50-75
18+ years	90
pregnant/ lactating	125
therapeutic range	upto 2000

Related topics:
Vitamin C (ascorbic acid)
Scurvy causes
Signs and symptoms
Treatment, cure and prevention.

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