Vitamin A

Vitamin A (Retinol) derived from beta-carotene, a provitamin which is transformed into retinol by the human organism . 

In food we can find both the retinol, and beta-carotene. Retinol comes from animal sources, while the beta-carotene from plant sources. Vitamin A is a fat soluble vitamin that is stored in the liver and the reserves can persist for years. Beta-carotene is deposited not only in the liver but also in adipose tissue. 

Vitamin A is necessary for the growth of bones, teeth, for the sexual maturation of the adolescent and adult fertility.
It strengthens the body against lung infections and is useful in treating acne. It maintains effective visual function and improves low-light vision.
It protects the skin from damage caused by excessive sun exposure. It 'a powerful anti-aging antioxidant: it fights free radicals and combats damage to the skin due to pollution and smoke and regulates cell growth and tissue regeneration. 

The major sources of retinol are animal sources: Cod liver oil, liver, butter, eggs The major sources of beta-carotene are: apricots, melons, parsley, hot peppers.

Excessive intake of retinol is harmful, so it is advisable to consume beta-carotene eating 2/3 apricots or a slice of melon a day.

The substances that support the transformation of the beta-carotene to vitamin A are vitamin C, vitamin E (it has the opposite effect if taken in high doses), zinc and proteins.

The B group Vitamins

The B vitamins, are vitamins which basic biochemical functions are distinct from each other, and they are called B vitamins because their natural food sources are the same (eg yeast), so any diseases caused by dietary deficiencies are never attributable to the lack of a single vitamin from the group B, but more frequently to a deficiency of all or nearly all.
 

The B vitamins act as coenzymes because facilitate the metabolism of carbohydrates, which are transformed into glucose used to produce energy. They also help the assimilation of proteins and lipids.

They are fundamental to the proper functioning of the nervous system.

If a person is tired, nervous and depressed, we can suspect a deficiency of B vitamins. 
Even a skin disorder such as acne or dry skin can be a sign of deficiency of the group B, that's because vitamins have also a plastic value as they facilitate the construction of new cells, help the skin of the hair and the liver.
 

The absorption of the vitamins of the B group is facilitated by the presence of Vitamin C, Vitamin E and by the presence of calcium.
 

These vitamins are water soluble so there are no problems due to overdoses since any excess is disposed of easily.

Apple

The apple is the most popular fruit.
It is synonymous with health and beauty.

It has many properties although it is not very rich in vitamins like other fruit. Its peel is rich in antioxidants of different types.

It does not contain protein and contains very little fat, for 85% of the apple is composed of water.

Apple is suitable for diabetics because it is a fruit that contains fructose that is a sugar that is metabolized without the use of insulin.
 

Contains pectin, a special fiber which controls the cholesterol levels. Apple helps fight bad cholesterol and help the good one.

As I said  before it is not a fruit with plenty of vitamins, in order of importance, the fruit in question you can find Vitamin C, Vitamin A, B1, and B2. 

The Vitamin C, in the apple, seems to be beneficial to the respiratory system and helps to defend against external attacks. 

Vitamin A present in the gut creates an enzyme that fights bacteria infected and this means that the apple is a disinfectant for the intestines. 

Vitamin B1 fights fatigue,loss of appetite and nervousness, while the B2 protects the mucous membranes of the mouth, hair and nails.

The apple is rich in minerals, especially potassium and  contains a trace of copper, a element that contributes to the constitution of the blood.

We anticipated that the apple is a powerful antioxidant. It is rich in bioflavonoids such as quercetin which helps to prevent cardiovascular disease and cancer.

In the peel there is a flavonoid naringin, which reduces the chance of getting lung cancer, prevents osteoporosis and Alzheimer's.