6 Complete the sentences about vitamins with the words from the box. One word is used twice.

immune system skin nervous system teeth eyes sunlight pregnancy large intestine antioxidant hemolytic anaemia metabolism blood stress brain enzymes

1. Vitamin A keeps the ... healthy and is important for good vision. It is found in fatty foods like butter, cheese, whole milk and yo­ghurt.

2. Vitamin A, and more specifically, retinoic acid, appears to main­tain normal ... health by switching on genes and differentiating keratinocytes (immature skin cells) into mature epidermal cells.

3. The В vitamins keep the ... healthy and help reduce... . They are found in foods like whole-grain bread and cereals.

4. Vitamin B₉ is needed before and during ... . It is present mainly in green leafy vegetables and legumes.

5. The primary role of vitamin B₆ is to act as a coenzyme to many other ... in the body that are involved predominantly in ... .

6. Vitamin B₁₂ is a water-soluble vitamin with a key role in the nor­mal functioning of the ... and nervous system, and for the forma­tion of... .

7. Vitamin С is needed to help the ... repair itself when it is damaged. It is found in fruit, especially citrus fruit and kiwifruit.

8. Vitamin D is needed for healthy bones and ... because it helps the body absorb calcium. Our body makes vitamin D when our ... is exposed to ... .

9. Vitamin E can be found most abundantly in wheat germ oil, and in sunflower or soybean oils. It is a fat-soluble ... that stops the production of reactive oxygen species formed when fat undergoes oxidation.

10. Deficiency of vitamin E is very rare but mild ... in newborn infants may occur.

11. Vitamin K₁ is found chiefly in leafy green vegetables such as spi­nach, cabbage, cauliflower and broccoli; some fruits such as avo­cado, kiwifruit and grapes are also high in vitamin K.

12. Many bacteria, such as Escherichia coli found in the ... , can syn­thesize vitamin К₂, but not vitamin K_1.

7. Say whether the following statements are true or false. Comment your answer.

1. A vitamin is a non-organic compound required as a nutrient in small amounts for the healthy maintenance of the whole organ­ism.

2. All vitamins are synthesized in sufficient quantities by an organ­ism.

3. Water-soluble vitamins dissolve easily in water, and as they aren't readily excreted from the body with the urine, their reserves can last for long periods.

4. Fat-soluble vitamins are absorbed through the intestinal tract with the help of lipids but they aren't likely to accumulate in the body.

5. Hypervitaminosis is more likely to be caused by water-soluble vi­tamins.

6. All vitamins of В complex have similar roles for our body and can be obtained only synthetically.

7. Retinol and other vitamers of vitamin A are necessary for healthy skin, development of the bones, and good vision.

8. Vitamin Kx is synthesized by intestinal bacteria, but vitamin Kj is found chiefly in leafy green vegetables and fruits.

9. Both avitaminosis and hypervitaminosis are similarly dangerous for a human body.

10. Restrictive diets have the potential to cause prolonged vitamin deficiency, which may result in potentially dangerous diseases.