According to the talk, how did vitamins lose in one’s body?

If you have a well-balanced diet, then you should be getting all the vitamins that you need for normal daily living. However, sometimes we think we’re eating the right foods but the vitamins are escaping, perhaps as a result of cooking and anyway we’re not getting the full benefit of them. Now, if you lack vitamins in any way, the solution isn’t to rush off and take vitamin pills. Though they can sometimes help. No, it’s far better to look at your diet and how you prepare your food. So what are vitamins? Well, the dictionary tells us they are "food factors essential in small quantities to maintain life". Now, there are fat soluble vitamins which can be stored for quite some time by the body and there are water soluble vitamins which need regular replacement in the body so a regular daily intake of these vitamins is needed.
OK, so how can you ensure that your diet contains enough of the vitamins you need? Well, first of all, you may have to establish some new eating habits! No more chips at the unit canteen, I’m afraid! Now firstly, you must eat a variety of foods. Then you need to ensure that you eat at least four servings of fruit and vegetables daily. Now you’ll need to shop two or three times a week to make sure that they’re fresh, and store your vegetables in the fridge or in a cool, dark place. Now let’s just refresh our memories by looking at the Healthy Diet Pyramid.
OK, can you all see that? Good. Well, now as you see, we’ve got three levels to our pyramid. At the top in the smallest area are the things which we should really be trying to avoid as much as possible. Things like...yes, sugar, salt, butter...all that sort of things.
Next, on the middle of our pyramid we find the things that we can eat in moderation. Not too much though! And that’s where we find milk, lean meat, fish, nuts, and eggs. And then at the bottom of the pyramid are the things that you can eat lots of! Because they’re the things that are really good for you. And here we have bread, vegetables and fruit. So don’t lose sight of your healthy diet pyramid when you do shopping.