Category: Nutrition

Vitamin A

What is Vitamin A ?

Vitamin A, is also called retinol, has multiple functions. it is important for growth and development, for the maintenance of the immune system and good vision.Vitamin A is needed by the retina of the eye in the form of retinal, necessary for both low-light  and color vision. In addition to helping the eyes adjust to dim light , vitamin A plays an important role in bone growth and metabolism , tooth development, reproduction, cell division, gene transcription, and regulation of the immune function  by strengthening it against infections. The skin, eyes, and mucous membranes of the mouth, nose, throat and lungs depend on vitamin A to remain moist and healthy. Vitamin A is also an important antioxidant that may play a role in the prevention of certain cancers.

Deficiency of  Vitamin A 

  • Night-blindness
  • Hyperkeratosis
  • Keratomalacia

Night blindness and very dry, rough skin may indicate a lack of vitamin A. Other signs of possible vitamin A deficiency include decreased resistance to infections, faulty tooth development, and slower bone growth. Since vitamin A is stored in the liver, it may take up to 2 years for signs of deficiency to appear. Xerophthalmia is very rare and usually due to malnutrition. Deficiencies cannot be compensated by postnatal supplementation.Vitamin A deficiency can occur as either a primary or a secondary deficiency. primary deficiency occurs among children and adults.Secondary vitamin A deficiency is associated with chronic malabsorption of lipids, impaired bile production and release, and chronic exposure to oxidants, such as cigarette smoke, and chronic alcoholism.

Good sources of vitamin A

Eating a wide variety of foods is the best way to ensure that the body gets enough vitamin A. The retinol, retinal, and retinoic acid forms of vitamin A are supplied primarily by foods of animal origin such as dairy products, fish and liver. Liver is a particularly rich source of vitamin A, it is advisable to have once in a week, as you may be at risk of having too much vitamin A.  Some foods of plant origin contain the antioxidant, beta-carotene, which the body converts to vitamin A. Beta-carotene, comes from fruits and vegetables, especially those that are orange or dark green in color. Vitamin A sources also include carrots, pumpkin, winter squash, dark green leafy vegetables and apricots, all of which are rich in beta-carotene.

How much Vitamin A do you need?

  • 0.7mg a day for men
  • 0.6mg a day for women

Recent studies indicate that vitamin A requirements may be increased due to hyperthyroidism, fever, infection, cold, and exposure to excessive amounts of sunlight. Those that consume excess alcohol or have renal disease should also increase intake of vitamin A.

Effects on having too much Vitamin A

Symptoms of vitamin A toxicity include dry, itchy skin, headache, nausea, and loss of appetite. Signs of severe overuse over a short period of time include dizziness, blurred vision and slowed growth. Vitamin A toxicity also can cause severe birth defects and may increase the risk for hip fractures.

Daily intake of vitamin A from food and supplements does not exceed 1.5mg. Having more than 1.5 mg allows for toxic levels of vitamin A to accumulate and  affect your bones – osteoporosis  especially for older people  and women. This is where your bone density reduces and you have a higher risk of fractures.If you eat liver every week, do not take supplements that contain vitamin A.If you are pregnant, do not take multivitamins containing vitamin A.


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Vitamins – Natural Supplements and Health benefits

 

What are vitamins?

vitaminsVitamins are essential nutrients your body needs in small amounts to work properly. Most people should get all the nutrients they need by eating a varied and balanced diet. Having much more than you need as  supplements, for too long can cause harmful effects.The body only needs small amounts of any vitamin.Vitamins are essential nutrients found in foods.They perform specific and vital functions in a variety of body systems, and are crucial for maintaining optimal health.

Classification:

There are 13 numbers of Vitamins. These Vitamins are classified into fat –soluble and water –soluble.

Vitamin foods

  1. Vitamin A
  2. Vitamin B1
  3. Vitamin B2
  4. Vitamin B3
  5. Vitamin B5
  6. Vitamin B6
  7. Vitamin B7
  8. Vitamin B9
  9. Vitamin B12
  10. Vitamin C,
  11. Vitamin D,
  12. Vitamin E,
  13. Vitamin K.

What are  fat-soluble vitamins ?
  • Fat-soluble vitamins are found mainly in fatty foods.
  • Body needs in small amounts to work properly
  • Body stores them in the liver and (adipose) fatty tissues for future use, when not used.
  • The body does not need these vitamins every day, they are there when you need them.
  • Fat-soluble vitamins will not be lost when the foods that contain them are cooked.
  • Having much more than you need, fat-soluble vitamins can be harmful and may lead to toxicity.
  • Eating a normal, well-balanced diet will be advisable.

Fat-soluble vitamins are:  Vitamin A, vitamin D,  vitamin E,  vitamin K

Fat-soluble foods are : Animal fats, including butter and lard, vegetable oils, dairy foods, liver and oily fish.

What are water-soluble vitamins ?
  • Water-soluble vitamins are found in fruit, vegetables and grains.
  • Water-soluble vitamins are not stored in the body and must be replaced each day.
  • We require a continuous daily supply in our diet.
  • These vitamins are easily destroyed or washed out during food storage and cooking preparation.
  • Proper storage and preparation of food is must.
  • Having much more than you need ,body gets rid of the extra vitamins when you urinate
  • Using megadoses of multivitamins or supplements is not recommended.
  • Eating a normal, well-balanced diet will be advisable.

Water-soluble vitamins are :  Vitamin C, and the B vitamins.

Water-soluble foods are : Citrus fruits, cereal grains, meat, poultry, eggs, fish, milk, legumes and fresh vegetables.


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