Benefits and side effects of Vitamin A

 

·         Vitamin A is a type of fat-soluble vitamin. It is not a single structure. It is composed of a group of similar molecules, including retinol and beta-carotene, the precursor of vitamin A.

·          Is the most common. Note 6

·         In the human body, vitamin A is mainly related to cell growth and differentiation, embryonic development, organ formation, immune function, and visual development.

·         Vitamin A benefits and side effects

Table of contents

·      What are the proven effects (benefits) of Vitamin A?

·      It is beneficial for children as they suffer from inflammation

·      Useful for pigmentary infections

·      The occurrence of diabetes

·      Promoting the health of young children

·      Cataracts, including age

·      Are there any side effects of vitamin A supplements?

·      Safety precautions (8 taboos for use)

·      What are the food sources of vitamin A?

·      Is there any blood in vitamin A supplements for pregnant women?

·      What are its vitamin A components?

What are the proven benefits of vitamin A?

1.   Useful for children with pneumonia

Pneumonia is defined as an acute infection of lung tissue caused by one or more associated pathogens, excluding specific bronchiolitis.

Respiratory syncytial virus is the major viral agent, found in 15% to 40% of pneumonia cases, followed by influenza A and B viruses, parainfluenza viruses, human pneumoniae viruses, and adenoviruses.

Childhood pneumonia is the single leading cause of death in children under five years of age. It is estimated that the incidence rate in this age group is 0.29 per year in developing countries and 0.05 per year in developed countries. Major risk factors include malnutrition, low birth weight, decreased immunity to measles, and indoor air pollution.

A meta-analysis of the literature (including 15 randomized controlled trials with a total of 3021 pneumonia patients) indicated that although vitamin A supplementation in addition to regular treatment cannot reduce mortality from childhood pneumonia, they improve the overall clinical response rate and shorten the treatment duration. It improves the duration of fever and cough, the time to clear signs, and reduces abnormal chest X-ray findings and length of hospital stay. Note 1

*Conclusion: Additional vitamin A supplementation in the treatment of pediatric pneumonia can help reduce clinical symptoms and signs and shorten hospitalization time.

  2. Beneficial for retinitis pigmentosa

Retinitis pigmentosa is a familial hereditary disease characterized mainly by the progressive degeneration of sensory cells in the retina. Early symptoms are mainly slow adaptation to darkness and night blindness, gradually affecting peripheral and central vision. In more severe cases, it can lead to blindness.

A double-blind trial (4 to 6 years in 601 patients with retinitis pigmentosa) found that vitamin A supplementation (15,000 IU per day) reduced deterioration of retinal function by 32% compared with placebo, as measured by electroretinography). Note 1

However, given the toxicity of large doses and incomplete research methods, further confirmation is needed.

3. Prevent diabetes

Diabetes is a complex metabolic disease associated with high blood sugar and impaired insulin action, mainly caused by poor diet and living habits and it is estimated that by 2030, more than 400 million adults will be affected worldwide.

Animal and human experiments have found that vitamin A can affect pancreatic beta cell production and insulin resistance, and its deficiency is positively associated with diabetes.

A retrospective study (193,803 Danes) found that eating more vitamin A (self-fortified dietary foods) in youth not only reduces the risk of diabetes in midlife and old age, but also reduces the incidence of diabetes in offspring. Note 2

The author stated that this finding is very important for low- and middle-income countries suffering from undernutrition, and is a simple and affordable nutritional intervention method.

4. Promoting the health of young children

According to a survey conducted by the World Health Organization, pneumonia, diarrhea and malaria top the list of causes of death among children under the age of five after the postnatal period. Diarrhea alone kills 500,000 children every year.

Malnutrition is the main cause of these diseases (45%), and is mainly linked to poor economic and health conditions, parasites, and chronic infections, especially in low- and middle-income countries.

The Cochrane Database of Systematic Reviews (Cochrane Database of Systematic Reviews, including 47 studies including 1,223,856 children over 6 months and under 5 years) indicated that vitamin A supplements could help reduce morbidity and mortality among young children. (Especially in reducing diarrhea and diarrhea). Measles events). Note 3

5. Reduce the risk of cataracts (age-related cataracts)

According to the World Health Organization, there are currently more than 37 million blind people in the world, and cataracts are the leading cause of blindness.

Although cataracts can be treated by intraocular lens replacement, some patients are still unable to receive appropriate treatment due to factors such as disparate medical resources and high cost. Therefore, it is important to take the right precautions

A meta-analysis of the literature (including 22 studies) indicated that higher intakes of vitamin A and beta-carotene could actually help reduce the risk of cataracts. Note 4

However, the author stated that since potential biases and interfering factors were not eliminated, the results still need to be confirmed.

6. Reducing the incidence of pancreatic cancer

Pancreatic cancer is one of the most difficult cancers of the digestive system and ranks fourth among the causes of cancer death, and about three-quarters of cases occur after the age of 65 years.

Because the early symptoms of pancreatic cancer are non-specific (such as loss of appetite, mild pain, nausea, and weight loss), people often lose their alertness. When they are diagnosed, about 80% of them are in the more severe intermediate and advanced stages and cannot be treated with surgery.

A meta-analysis of the literature (including 11 studies) indicated an inverse association between vitamin A intake and the incidence of pancreatic cancer. People who eat larger amounts can reduce their risk by about 16% (compared to those who eat larger amounts) less. ). Note 5

Are there any side effects of vitamin A supplements?

For most healthy people, taking vitamin A in moderation from food is safe and has no side effects. If you use health supplements, you should pay attention to the dosage to avoid overdose and long-term poisoning.

In general, toxicity is typically associated with long-term use of more than 10 times the Recommended Dietary Allowance (RDA), approximately 25,000 to 33,000 IU per day.

Symptoms of acute and chronic vitamin A poisoning include nausea, headache, hair loss, fatigue, loss of appetite, dizziness, dry skin, peeling, cerebral edema, hepatosplenomegaly, bone and joint pain, etc. Severe cases can lead to liver damage, bleeding and coma.

Safety precautions (8 contraindications for use)

There is evidence that some groups are more susceptible to vitamin A toxicity when taken orally, even at lower doses, including the elderly, long-term alcoholics, and patients with familial hyperlipidemia.

Long-term use of high doses may increase osteoporosis and hip fractures, especially in older adults

Pregnant women, children, and people with poor liver and kidney function who wish to take additional supplements should inform medical staff first to ensure safe use.

Please be careful if you have low blood pressure or are taking antihypertensive medications as they may cause low blood pressure

It may have an anticoagulant effect, so please be careful if you have blood-clotting disorders or are taking anticoagulants.

Concurrent use of high-dose vitamin A and tetracycline antibiotics may increase the risk of intracranial hypertension.

Orlistat (obesity medication) and cholesterol-lowering medications (bile acid sequestrants) may inhibit vitamin A absorption.

Do not use it with omeprazole (Prilosec, a gastrointestinal drug) or the chemotherapy drug doxorubicin (Doxorubicin), because it may affect the effect of the drug.

What are the food sources of vitamin A?

Natural vitamin A (retinyl palmitate form) is commonly found in beef, animal liver, eggs, cod liver oil, dairy products, whole milk, and cheese.

In addition, beta-carotene is the precursor to vitamin A. Vitamin A content can also be increased by consuming foods rich in related carotenoids (such as dark green vegetables, yellow or orange vegetables and fruits): common foods such as spinach, papaya, sweet potatoes, carrots, pumpkin, peaches, mango, etc.

Are there any risks in taking vitamin A supplements for pregnant women?

Although adequate vitamin A is important for fetal development, excessive intake early in pregnancy may increase the risk of fetal abnormalities.

Therefore, pregnant women and breastfeeding mothers should y special attention to their total intake (daily intake of food and health products should not exceed 5,000 IU) to avoid harmful consequences.

In addition, synthetic forms of vitamin A (commonly used in high-dose supplements for formal medical treatment) may cause serious birth defects in fetuses and should therefore be avoided. Related forms include acitretin, bexarotene, isotretinoin, and tazarotene

What is the recommended amount of vitamin A?

According to the recommended dietary allowance standards set by the Institute of Medicine (IOM):

Children

0 to 6 months: 400 mcg daily

7 to 12 months: 500 mcg daily

Children

From 1 to 3 years: 300 micrograms daily

From 4 to 8 years: 400 micrograms daily

From 9 to 13 years: 600 micrograms daily

Pikes

Teenagers and adults

Males aged 14 years and over: 900 micrograms daily

Women aged 14 years and over: 700 micrograms daily

(For women, it can increase to 770 micrograms during pregnancy and 1,300 micrograms during breastfeeding)

1 microgram is equivalent to 3.33 IU of vitamin

Conclusion

Vitamin A, a fat-soluble vitamin containing retinol and beta-carotene, is crucial for cell growth, differentiation, and immune function.

It has numerous benefits for children, especially those suffering from inflammation, pigmentary infections, diabetes, and cataracts.

Vitamin A can reduce the risk of pneumonia, retinal degeneration, diabetes, and pancreatic cancer.

It also promotes the health of young children, reduces morbidity and mortality, and reduces the incidence of pancreatic cancer.

However, side effects of vitamin A supplements include nausea, headaches, hair loss, fatigue, and severe liver damage.

Long-term use may increase osteoporosis and hip fractures.

Pregnant women, children, and those with poor liver and kidney function should consult medical staff before taking vitamin A supplements.

It is important to be cautious with low blood pressure, blood-clotting disorders, concurrent use of high-dose vitamin A and tetracycline antibiotics, orlistat and cholesterol-lowering medications.

Vitamin A is found in beef, animal liver, eggs, cod liver oil, dairy products, whole milk, and cheese. Excessive intake early in pregnancy may increase the risk of fetal abnormalities.

Pregnant women and breastfeeding mothers should limit their daily intake to 5,000 IU. Synthetic forms of vitamin A should be avoided.