vitamin C properties
Vitamin C , also known as ascorbic acid, is a water-soluble vitamin that is naturally found in some foods and added to some ingredients. You can also get vitamin C supplements.
Unlike most animals, humans cannot synthesize vitamin C in their bodies, so they must obtain it through food. Vitamin C is necessary for the biosynthesis of collagen, l-carnitine, and some neurotransmitters. This vitamin is also involved in protein metabolism. As you know, collagen is one of the essential components of connective tissue that plays a very important role in wound healing .
Vitamin C is an important physiological antioxidant that various studies have shown that it can stimulate the production of other antioxidants in the body. Various studies have been conducted on the effect of vitamin C in preventing or delaying the growth and development of certain cancer cells, cardiovascular disease and other diseases in which oxidative stress plays a vital role.
In addition to its biosynthetic and antioxidant function, vitamin C plays a very important role in the functioning of the immune system and improving the absorption of “other iron” from “iron in plant foods.”
Vitamin C deficiency causes a condition called scurvy , which is characterized by fatigue or weakness, diffuse connective tissue weakness, and weak capillaries. Cells store vitamin C through specific carrier proteins.
In laboratory studies, scientists have found that oxidized vitamin C, or dehydrosorbic acid, enters cells through some glucose transporter and is then internally reduced to ascorbic acid. The physiological significance of the absorption of dehydrocorbic acid and its role in vitamin C remains unknown.
Oral vitamin C produces plasma concentrations that must be completely controlled. Approximately 70 to 90% of vitamin C is absorbed by taking 30 to 180 mg of it daily. However, at doses above 1 gram per day, the absorption of this vitamin is less than 50% and the unmetabolized ascorbic acid enters the urine and is excreted from the body.
Results of pharmacokinetic studies show that an oral dose of 1.25 g / day of ascorbic acid produces a mean plasma concentration of 135 μmol / L, which is twice the amount obtained from consuming 200 to 300 mg of ascorbic acid from foods rich in it. It is vitamin C.
Pharmacokinetic modeling results predict that even a 3 g dose consumed every 4 hours could produce a plasma concentration of 220 μL / L. The total vitamin C content in the body will vary from 300 mg to 2 grams.
High levels of vitamin C are stored in cells and tissues and are higher in leukocytes (white blood cells), eyes, adrenal glands, pituitary gland, and brain. Relatively low levels of vitamin C (micromolar concentration) are found in extracellular fluids, such as plasma, red blood cells, and saliva.
Take vitamin C a day
The recommended intake of Vitamin C and other minerals has been developed based on various sources. DRI is a general term for a set of reference values used in planning and evaluating dietary intake. These values, which vary by age and gender, include the following:
- Recommended Recommended Amount (RDA): The average recommended daily intake level to meet the needs of healthy people.
- Proper Consumption (AI) : It develops when there is evidence of insufficient RDA.
- High intake (UL): The maximum daily intake that is not likely to cause side effects.
Table 1 shows the RDA for Vitamin C. The RDAs for Vitamin C are based on its antioxidant function and the physiological function in white blood cells and are usually higher than required to protect the body from deficiency. For babies from birth to 12 months old, FNB has released the right amount of AI Vitamin C.
Table 1: The recommended tolerable intake of vitamin C.
|0-6 months||40 mg *||40 mg *|
|7-12 months||50 mg *||50 mg *|
|1-3 years||15 mg||15 mg|
|4-8 years||25 mg||25 mg|
|9-13 years old||45 mg||45 mg|
|14-18 years old||75 mg||65 mg||80 mg||115 mg|
|19+ years old||90 mg||75 mg||85 mg||120 mg|
|Smokers||People who smoke will need 35 mg more vitamin C than others.|
Proper Consumption (AI)
Best sources of vitamin C:
Foods that contain vitamin C:
And are On vegetables vegetables fruits The Best Source Of the C Vitamin . Citrus fruits, tomatoes, tomato juices, and potatoes are the largest sources of vitamin C in the American diet .
Other healthy food sources include red and green peppers, kiwi, broccoli, strawberries, Brussels sprouts, and cantaloupe.
Although there is no naturally occurring vitamin C in cereals, breakfast cereals can be fortified with vitamin C.
The content of vitamin C in foods may decrease with prolonged storage and cooking because ascorbic acid is soluble in water and hydrolyses. It can reduce its steaming and put it in the microwave.
Fortunately, most foods that are a great source of vitamin C can usually be eaten raw. Consuming 5 different servings of vegetables and fruits per day can provide more than 200 mg of vitamin C.
Table 2: Selected sources of vitamin C supply to the body
|food||Mg per serving||Percentage (%) DV *|
|Red pepper, sweet, raw, half a cup||95||158|
|Portuguese water, three-fourths of the scale||93||155|
|Portugal average number||70||117|
|Grapefruit juice, three to four servings||70||117|
|Kiwi, medium number||64||107|
|Green pepper, sweet, raw, half a cup||60||100|
|Cauliflower, cooked half a cup||51||85|
|Fresh strawberries, half a cup||49||82|
|Brussels sprouts, cooked half a cup||48||80|
|Half a medium grapefruit||39||65|
|Broccoli, half serving||39||65|
|Tomato juice three quarters of a cup||33||55|
|Melon, half a cup||۲۹||48|
|Cabbage, cooked half a cup||۲۸||47|
|Raw cauliflower half a cup||۲۶||43|
|Medium cooked potatoes||12||۲۸|
|Raw tomato is medium in number||12||۲۸|
|Spinach, cooked half a cup||9||12|
|Frozen green peas half a cup||8||13|
DV stands for Daily Value. DVs were developed by the Food and Drug Administration and help people compare the nutritional content of products in their diet. The daily value for vitamin C is approximately 60 mg for adults and children 4 years and over.
The FDA required all food manufacturers to mark the amount of vitamin C available on their products and indicate their DV. Foods with 20% DV or more are a rich source of nutrients.
Vitamin C supplements:
Dietary supplements usually contain vitamin C in the form of ascorbic acid, which has the bioavailability of the natural equivalent of ascorbic acid in foods such as orange juice and broccoli.
Other forms of vitamin C supplements include sodium ascorbate, calcium ascorbate, other mineral ascorbates, ascorbic acid with bioflavonoids, and hybrid products such as Ester-C, which contain calcium ascorbate, dehydrocorbate, calcium thronate, xylonate, and lexons. Few human studies have examined the bioavailability and differences between different forms of vitamin C.
In one study, Ester-C and ascorbic acid produced the same concentrations of vitamin C in plasma, but Ester-C produced higher concentrations of vitamin C in white blood cells 24 hours after ingestion; another study found no difference in plasma vitamin C levels. Or there is no urine excretion of vitamin C among the three different sources of vitamin C.
Vitamin C consumption and statistics:
According to a study by the National Institutes of Health and Nutrition from 2001 to 2002, the average vitamin C intake was 150.2 mg per day for an adult male and 83.6 mg per day for an adult female.
The average intake for children and adults in the age group 1 to 18 years ranges from 75.6 mg daily to 100 mg daily. Although this study does not include data available to infants and young children, breast milk is a good source of vitamin C.
Vitamin C supplements are very common, which increases the amount people eat. Data from the National Institutes of Health and Nutrition from 1999 to 2000 showed that approximately 35% of adults took vitamin supplements, which usually contain vitamin C as an ingredient.
The results also show that 12 percent of these people take separate supplements to supplement their bodies with vitamin C. According to this information, approximately 29% of children receive the amount of vitamin C they need as a supplement. Often, the level of vitamin C in the body is checked by measuring its levels in the plasma.
Other measurements, such as the concentration of vitamin C in white blood cells, can accurately indicate the level of this vitamin in the tissues, but it is very difficult to evaluate it in this way and its results cannot always be guaranteed.
Vitamin C deficiency in the body:
Severe deficiency of vitamin C in the body leads to scurvy . The time period for the development of this disease is very variable and depends on the body’s storage of vitamin C, but its symptoms will appear within a month or less. Early signs include fatigue, weakness, and gingivitis.
With the development of vitamin C deficiency, collagen synthesis weakens and connective tissues become weaker. This will lead to petechiae, bruising, purpura, joint pain, poor wound healing, and hyperkeratosis (an increase in the stratum corneum of the epidermis which is dead cells).
Other symptoms of scurvy include depression as well as swelling, bleeding gums, and loss or loosening of teeth due to weak tissue. Iron deficiency anemia may also occur due to increased bleeding and decreased iron absorption.
Bone disease may also develop in children. It can be fatal if left unchecked. By the end of the eighteenth century, most sailors who traveled long distances and did not get enough vitamin C were more likely to develop the disease.
In the mid-eighteenth century, British sailor James Lind conducted an experiment and concluded that consuming citrus fruits or their juice could treat scurvy. Vitamin C deficiency and scurvy are rare in today’s developed countries. Overt deficiency symptoms only occur when vitamin C intake has been less than 10 mg per day for several consecutive weeks.
Vitamin C deficiency is not very common in developed countries, but it can still occur in some people.
Groups at risk of developing a vitamin C deficiency:
Vitamin C deficiency occurs below the specified RDA. The following groups are more likely to have a vitamin C deficiency than others.
Smokers and people who live next to smokers:
Ongoing studies show that smokers have lower plasma concentrations of vitamin C than nonsmokers. This is due to oxidative stress. As a result, the International Organization for Migration has found that smokers need 35 mg of vitamin C per day more than non-smokers.
Exposure to cigarette smoke can also lower levels of vitamin C in the body. These people need to make sure they get enough of this vitamin throughout the day.
Infants who are breastfed with boiled or steamed milk:
Most babies in developed countries are breastfed and therefore receive adequate amounts of vitamin C. For a variety of reasons, it is not recommended to feed a baby boiled or steamed cow’s milk. Because eating it causes a deficiency of vitamin C in infants, and this is because cow’s milk contains low levels of vitamin C, and heating it can destroy this vitamin.
People with limited dietary diversity:
Although fruits and vegetables are the best source of vitamin C, there are other foods that are rich in this nutrient. Therefore, this deficiency can be prevented by adopting a varied diet. People with limited dietary diversity may not get enough vitamin C. These include the elderly, people with limited consumption, alcoholics, people with mental illnesses, and children who refuse to eat certain foods.
People with malabsorption or certain illnesses:
Some medical conditions can reduce the absorption of vitamin C. People with acute intestinal malabsorption or chronic disease are more likely to have a vitamin C deficiency. Low vitamin C concentrations may also be observed in patients with late-stage kidney disease or chronic hemodialysis.
Vitamin C Health Benefits:
Because this vitamin works as an antioxidant and plays a very important role in the functioning of the immune system, it helps prevent and treat various diseases. This section focuses on 4 diseases and disorders that the use of vitamin C may play an important role in treating and preventing.
These diseases include cancer (prevention and treatment), cardiovascular disease, age-related degeneration, cataracts, and the common cold.
Vitamin C for cancer prevention:
Epidemiological evidence suggests that eating more fruits and vegetables is associated with a lower risk of many types of cancer. This is due to the high levels of vitamin C present in these substances.
As you know, vitamin C limits the formation of carcinogens such as nitrosamines in the body, balances the immune system response, and due to its antioxidant function it can reduce the oxidative damage that leads to cancer.
Most case studies showed that there is an inverse association between daily vitamin C intake and cancers of the lung, breast, intestine, anus, stomach, mouth, throat, or esophagus. Plasma vitamin C concentrations are also lower in people with cancer. However, evidence from various studies shows that such results are not consistent because vitamin C intake varies from study to study.
In one study, 82,234 women between the ages of 33 and 60 were studied. The average consumption of these subjects was around 205 mg per day, which was obtained from food. Compared to people who consumed only 70 mg of vitamin C per day, they were 63% less likely to develop breast cancer.
In contrast, Cauchy and colleagues found no lower risk of breast cancer among postmenopausal women who took at least 198 mg of vitamin C per day compared to women who consumed 87 mg per day.
A study by Kar and Frey found that the vast majority of studies to date had not reported a reduced risk of cancer, and most of the participants were high in vitamin C. Studies reporting a lower risk of cancer show that people who eat at least 80 to 100 milligrams of vitamin C per day have a lower risk of developing cancer.
Evidence from randomized clinical trials indicates that vitamin C supplementation, usually combined with other micronutrients, has no effect on cancer risk. In one study, 13,017 healthy adults received antioxidant supplements with 120 mg of ascorbic acid, 30 mg of vitamin E, 6 mg of beta-carotene, 100 mg of selenium, and 20 mg of zinc.
After a controlled period of 7.5 years, antioxidant supplements reduced the incidence of cancer in men, but they did not work in women. Additionally, basic antioxidant status has been associated with a cancer risk in men but not in women. Supplementing with 500 mg of vitamin C daily, plus 400 units of vitamin E daily, did not reduce the risk of prostate or other cancers for eight years.
Similar results were found in women who participated in one study. Compared to the placebo study (used in place of drugs that are similar to drugs but only contain natural ingredients), taking a vitamin C supplement for 9.4 years had a significant effect on cancer incidence or death. Mir did not have.
In one large trial, daily intake of vitamin C supplements plus molybdenum (30 micrograms) for 5 to 6 years had no significant effect on the risk of developing esophageal or stomach cancer. Additionally, during a 10-year follow-up, this type of diet combined with supplementation failed to have a significant effect on mortality from cancers of the esophagus, stomach and others.
A 2008 review found that vitamin C supplementation and other antioxidants were not very helpful in preventing gastrointestinal cancer, and no convincing evidence was found. A similar study by Coulter et al. Found that taking a vitamin C supplement along with vitamin E had no significant effect on the risk of cancer death.
Meanwhile, there is no firm evidence that dietary vitamin C intake is effective against cancer. Results of most clinical trials indicate that vitamin C supplementation alone or in combination with other nutrients may not be helpful for cancer prevention.
There are significant limitations to interpreting many of these studies, and that is that researchers did not measure vitamin C concentrations before and after taking the supplement. Vitamin C concentrations in plasma and tissues are well controlled in humans.
At a daily intake of 100 mg or more, the cells are saturated, and at a dose of at least 200 mg, the concentration of this vitamin in the plasma increases only slightly. If a person’s vitamin C level was close to saturation at the start of the study, then supplementation would have little effect on the measured results.
Vitamin C treatment for cancer:
In 1970, a study by Cameron, Campbell, and Bowling showed that high doses of vitamin C have a positive effect on a person’s quality of life and the survival time of cancer patients. However, some other studies did not support these results.
In the Moertel study, patients with advanced bowel cancer received about 10 grams of vitamin C per day but the chances of a cure were minimal. The authors of a 2003 study looked at the effects of vitamin C on advanced cancer patients, and concluded that taking vitamin C had no significant effect on cancer mortality.
Other research shows that the type of vitamin C intake can explain the results of these studies well. Most intervention trials have only tested oral and oral administration. However, in some cases, such as the Cameron study, a combination of oral and intravenous administration has been studied.
Taking vitamin C by mouth, even in high doses, can increase the plasma concentration of this vitamin to a maximum of 220 μmol per liter. However, intravenous consumption may result in a plasma concentration of 26,000 μmol per liter. Research in mice indicates that a dose of intravenous vitamin C is promising for tumors that are difficult to treat.
High concentrations of this vitamin may act as a pro-oxidant and produce hydrogen peroxide, which has a selective toxicity to cancer cells. Based on these findings and other case reports in advanced cancer patients after taking high doses of vitamin C as intravenously, some researchers have supported high doses of C for cancer treatment.
As discussed below, there is still no certainty about taking vitamin C supplements and other antioxidants and their interaction with chemotherapy and radiotherapy. Therefore, people who undergo these procedures should consult a doctor before taking vitamin C or other high-dose antioxidant supplements.
Vitamin C properties for cardiovascular disease:
Evidence from various studies indicates that higher consumption of fruits and vegetables is associated with a lower risk of cardiovascular disease. This link may be due to the antioxidant content of these substances.
In addition to its antioxidant properties, vitamin C can reduce monocyte dependence on the endothelium, improve endothelial-dependent nitric oxide production, and reduce the incidence of cardiovascular disease.
The results of studies examining the link between vitamin C intake and heart disease risk are very confusing. In one study, which began with a 16-year perspective, 85,118 nurses were surveyed.
General intake of vitamin C through food and supplements was inversely related to the risk of developing cardiovascular disease. However, dietary intake of vitamin C did not show any evidence for this. This indicates that users who take vitamin C supplements may have a lower risk of developing coronary heart disease.
A smaller study found that women with postmenopausal diabetes who took at least 300 mg of a vitamin C supplement per day were more likely to die from cardiovascular disease.
A study of 20,649 British adults found that people in the top quartile of plasma vitamin C concentrations were 42 percent less likely to have a stroke. In the male physicians participating in the Physicians’ Health Study, vitamin C supplementation for an average of 5.5 years was not associated with a significant reduction in mortality from cardiovascular disease or deaths from coronary heart disease.
An analysis of nine studies involving 293,172 participants without heart disease found that people who took more than 700 mg of a daily vitamin C supplement were 25% less likely to develop the disease. Results of clinical interventions were not able to confirm the positive effect of vitamin C supplementation on primary or secondary prevention of cardiovascular disease.
In the Women’s Cardiovascular Study, the secondary prevention trial included 8,171 women aged 40 or over with a history of cardiovascular disease. They received 500 mg of vitamin C daily for 9.4 years. The results showed no comprehensive effect on cardiovascular disease. Likewise, supplementing with vitamin C for an average of 8 years had little effect on cardiovascular disease in the men under control.
Other clinical trials have generally studied the effect of vitamin C supplementation with other antioxidants, such as vitamin E and beta-carotene, on cardiovascular disease. Such tests make it difficult to isolate and quantify the effect of vitamin C.
The SU.VI.MAX study The effect of a combination of vitamin C (120 mg per day), vitamin E (30 mg per day), beta-carotene (6 mg per day), selenium (100 mcg per day) and zinc (20 mg per day) in 13017 French adults From the general population. After 7.5 years, the combination supplements had no effect on cardiovascular disease in both men and women.
In another study, about 423 postmenopausal women with at least one coronary artery stenosis were examined. In this study, supplementation with 500 mg of vitamin C plus 400 units of vitamin E twice a day not only had any heart benefit, but also increased mortality compared to a placebo.
The study authors concluded after their studies that antioxidant supplements (vitamin C, vitamin E, beta-carotene or selenium) did not affect the development of atherosclerosis. Likewise, a systematic review of the effect of vitamin C on the prevention and treatment of cardiovascular disease found that this vitamin does not have a significant effect on preventing cardiovascular disease.
The researchers released follow-up data from clinical trials conducted in China. In this study, daily vitamin C supplementation (120 mg) plus molybdenum (30 micrograms) for 5 to 6 years significantly reduced the risk of cerebrovascular death by 8%.
Although this trial confirmed the benefits of using these supplements, in general, the results of most of the overlapping trials failed to provide convincing evidence of the effect of vitamin C supplementation in protecting and preventing cardiovascular disease or reducing mortality. .
However, as mentioned in the section on cancer prevention, clinical trials and data are limited for vitamin C because concentrations of this vitamin are controlled in plasma and tissues in humans.
If a person’s vitamin C level was close to saturation at the start of the study, the supplement had almost no effect on the results measured.
Age-related macular degeneration (AMD) and cataracts:
AMD and cataracts are the two main causes of vision loss in the elderly. Oxidative stress may contribute to these conditions. Researchers believe that vitamin C and other antioxidants play an important role in the prevention and treatment of these diseases.
A population study in the Netherlands found that adults age 55 and older who consumed high amounts of vitamin C plus beta-carotene, zinc, and vitamin E had a lower risk of developing AND. However, most studies do not support these results.
The authors of a systematic review in 2007 concluded that current evidence does not support the role of vitamin C and other antioxidants as antioxidant supplements in early prevention of AMD. Although research has not shown that antioxidants play a significant role in the development of AMD, some evidence suggests that such conditions may slow the development of AMD.
Age-related eye disease study: The effect of a high dose of selected antioxidants (500 mg vitamin C, 400 units of vitamin E, 15 mg beta-carotene, 80 mg zinc and 2 mg copper) on advanced AMD development among 3597 tested adults older adults with varying degrees of AMD. After 6.3 years, participants at high risk of developing advanced AMD who received antioxidant supplements had a 28% lower risk of developing AMD.
A high intake of vitamin C in the diet and high plasma concentrations were associated with a reduced risk of developing cataracts. In a five-year study in Japan, researchers found that high intake of dietary vitamin C was associated with a reduced risk of developing cataracts in 30,000 people between the ages of 45 and 64.
The results of two case studies also show that taking more than 300 mg of vitamin C per day can reduce the risk of developing cataracts by 70 to 75%. On the other hand, taking vitamin C supplements was associated with an increased risk of age-related cataracts by 25%. These results applied to study participants who took relatively high doses of vitamin C supplements.
Data from clinical trials is limited. In one study, Chinese adults who took 120 mg of a daily vitamin C supplement plus 30 micrograms of molybdenum for five years failed to significantly reduce the risk of developing cataracts. However, adults aged 65-74 who received 180 mg of vitamin C plus 30 mcg of molybdenum along with other nutrients in a mineral / vitamin supplement had a 43% lower risk of developing cataracts.
In a study of AREDS, older adults who took 500 mg of a vitamin C supplement, 400 units of vitamin E, and 15 mg of beta-carotene for 6.3 years did not show a significant reduction in the development or progression of cataracts.
In general, current evidence does not indicate that vitamin C (taken alone or in combination with other antioxidants) might affect the development of AMD.
However, some evidence suggests that the AREDS combination might slow the progression of AMD in people at risk of developing advanced AMD.
Vitamin C for colds:
In 1970, Linus Pauling suggested that vitamin C could be successful in treating or preventing the common cold. Results of controlled studies are contradictory, leading to confusion and discord. A 2007 review reviewed controlled trials. This study involved using at least 200 mg of vitamin C per day.
Prophylactic use of vitamin C cannot significantly reduce the risk of developing the common cold in the general population. However, in an experiment that included marathon runners, soldiers, and skiers, preventive use of vitamin C at a dose of about 250 mg per day to 1 gram per day was able to reduce the risk of developing the common cold by up to 50% .
In the general population, preventive use of vitamin C reduced the duration of the common cold by an average of 8% in adults and 14% in children. If vitamin C is taken after symptoms appear, it will not affect the duration of the common cold and the severity of symptoms.
In general, evidence to date suggests that taking vitamin C regularly in doses of at least 200 mg per day does not reduce the risk of developing the common cold, but such consumption can help people who are exposed to strenuous exercise or a cold environment. slowly
Taking vitamin C supplements might reduce the duration and severity of the common cold. This is due to the antihistamine properties of the high doses of Vitamin C. However, taking vitamin C after cold symptoms appear may not be helpful.
Risks of taking too much vitamin C:
As you know, Vitamin C is considered to be very low in toxicity and most people believe that high consumption does not cause serious side effects. The most significant and most common side effects of an overdose are diarrhea, nausea, abdominal cramps, and other gastrointestinal disturbances due to the osmotic effect of vitamin C that is not absorbed in the gastrointestinal tract.
In postmenopausal women with diabetes, vitamin C supplementation is significantly associated with an increased risk of death from cardiovascular disease. In fact, the mechanism of this effect is still unknown, and these results have been obtained from a small number of patients. No such association has been observed in other studies. Therefore, the significance of these results remains unclear.
Taking too much vitamin C increases the possibility of increased excretion of urine oxalate and uric acid (which may lead to kidney stones, especially in people with kidney disorders). However, evaluation of these effects is confusing, and it is not yet known if vitamin C is involved in kidney stone formation. The best evidence that vitamin C is involved in the formation of kidney stones is in hyperoxalurate patients.
Due to enhanced iron absorption of vitamin C, the theoretical concern is that high intake of vitamin C could lead to elevated iron absorption. In a healthy person, this is not a concern. However, in people with hereditary hemochromatosis, high levels of vitamin C can worsen iron overload and lead to tissue damage.
Under certain conditions, vitamin C can act as a pro-oxidant and contribute to oxidative damage. Few studies have indicated that by acting as a pro-oxidant, taking vitamin C orally as a supplement can damage chromosomes and DNA. However, other studies have not shown increased oxidative damage.
Other reported effects from high vitamin C intake include decreased levels of vitamin B12 and copper , an acceleration of metabolism, or excretion of ascorbic acid in the urine. Enamel erosion or allergic reactions. However, at least some of these conclusions were the result of synthetic methods.
FNB has sought to develop ULs for vitamin C that can be applied to vitamin C supplements through food or nutritional supplements. Long-term intake of vitamin C above UL might increase the risk of some diseases and have more side effects. ULs do not apply to people using vitamin C for therapeutic purposes.
Table 3: Tolerable High Intake of Vitamin C.
|Omar||a leg||female||pregnant women||I turn to milk|
|0-12 months||It cannot be published||It cannot be published|
|1-3 years||400 mg||400 mg|
|4-8 years||650 mg||650 mg|
|9-13 years old||1200 mg||1200 mg|
|14-18 years old||1800 mg||1800 mg||1800 mg||1800 mg|
|19+ years old||2000 mg||2000 mg||2000 mg||2000 mg|
Vitamin C interactions with medications:
Vitamin C supplements may interact with some medications. Some examples are listed below. People who regularly take these medications should consult a doctor before taking vitamin C and supplements.
Vitamin C, chemotherapy and radiation therapy.
Scientists and researchers widely discuss the safety and effectiveness of taking vitamin C and other antioxidants during cancer treatment. Some data indicate that antioxidants may protect cancer cells from the activity of radiotherapy and chemotherapy agents such as cyclophosphamide, chloromposil, carmustine, busulfan, tuba, and doxorubicin. At least some of this data has been criticized for poor study design.
Other studies have suggested that antioxidants may protect normal tissues from chemical damage. However, due to the strict physiological control of vitamin C, it is not yet clear whether orally taking vitamin C supplements can alter vitamin concentrations sufficiently to produce the suggested effects. People undergoing chemotherapy or radiation therapy should consult a doctor before taking vitamin C or other antioxidants.
Vitamin C, along with other antioxidants, might reduce the increase in HDL levels. It is not yet known if this interaction would occur with other fat-modifying diets. Your doctor should check your lipid level in people who take antioxidant supplements.
Vitamin C and a healthy diet:
Most experts believe that people’s nutritional needs should primarily be met by food. Nutrient-rich foods can contain vitamins and minerals and provide the fiber your body needs. In some cases, nutritional supplements and fortified foods may be helpful in providing one or more nutrients.
The Dietary Guidelines for Americans describe a healthy eating pattern as one of the following:
- It includes a variety of vegetables, fruits, whole grains, low-fat milk, and healthy oils.
- Fruits such as citrus fruits, various juices and vegetables are good sources of Vitamin C.
- This diet should include protein foods such as seafood , lean meat , turkey, chicken, lentils, eggs, nuts, seeds, and soy products.
- Limit saturated fat, sugar and sodium.
- The calorie intake should be limited to the daily requirement.