Vitamin A is fat-soluble vitamin. Vitamin A is a versatile vitamin, known to regulate the expression of several hundred genes. And major role include:
1. Promoting vision
2. Participating in protein synthesis and cell differentiation thereby maintaining the health of epithelial tissues and skin.
3. Supporting reproduction and regulating growth.

Excellent food source
The richest sources of vitamin A are food derived from animals- liver, fish liver oil, milk  and milk products, butter and eggs. Because vitamin A is fat soluble. But many vegetables and some fruits contain vitamin A precursors. Dark leafy greens (like broccoli and spinach)

Interesting facts
My friend, she really love to eat pumpkin and her skin turns yellowing. Now, I understand why her skin yellowing. Because she get high level of Beta-carotene and Beta-carotene is stored just in the fat under the skin. So overconsumption of beta-carotene from food may turn the skin yellow. 

1.Large and cooperative bone-making and maintenance team composed of nutrients and other compounds

2.Protect against cognitive decline and slows the progression of Parkinson disease.

3.Vitamin D in muscle cells encourages growth in children and preserves strength in adults.
4.Signals cell of the immune system and defend against infectious disease. 

Excellent food source
2 cups of vitamin D-fortified milk a day. Egg yolks, oily fish such as Salmon, Mackerel, Sardines are the best natural sources of vitamin D.

And vitamin D differs from the other nutrients because we can synthesize it with the help of sunlight. So we can get Vitamin D from sunlight. 

Interesting facts
We can synthesis Vitamin D with sunlight. And the pigment of dark skin required more sunlight exposure than light-skinned people-perhaps as much as 4 to 6 times longer. 

Excellent food source
Folate is especially abundant in legumes, fruits, liver, and leafy vegetables. 

Interesting facts
Medicine have effect to folate in our body. Aspirin and antacids can interfere with the body’s folate status: aspirin inhibits the action of folate-requiring enzymes, and antacids limit the absorption of folate. 

And vitamin E is participation in bone building and recently discovered proteins needing vitamin K’s assistance. These proteins have been identified in the plaques of atherosclerosis, the kidneys, and the nervous system. 

Excellent food source
Green leaves vegetables such as spinach, fruits are avocado and kiwi, and also in soy beans.

Moreover, bacteria in our GI tract synthesize vitamin K, although the amount is insufficient to meet the body’s needs. 

Interesting facts
I never know the new born infants are born with a sterile intestinal tract so it present a unique case of vitamin K. And vitamin K-produce bacteria take 2 weeks to establish themselves. So to prevent hemorrhagic disease (blood-clotting factors is lacking) in the newborn, a single dose of vitamin K is given at birth by intramuscular injection.