That the health was good, it is necessary to increase immunity, that is ability of an organism to resistance to various infections, bacteria. Various vitamins which contain in food are for this purpose necessary. Most of all vitamins and mineral substances contain in the most usual vegetables.
Where most of all vitamins
Certainly, contains in vegetables and fruit most of all useful to an organism, vitamins. Such usual vegetables as carrots, beet, tomato, cabbage, parsley, fennel, spinach, green onions — are, without exaggeration, the real well of vitamins, amino acids and mineral substances without which any person won't be able to do. Of course, it is difficult to allocate ""most useful"" as each vegetable contains substances which are necessary for strengthening of any given system of a human body, for example cardiovascular, nervous, muscular or a brain.
What is avitaminosis
When daily consumption of vegetables considerably decreases, and there is no equivalent replacement of vitamins and mineral substances necessary for an organism, avitaminosis begins (or other diseases) which strongly weaken immunity and an organism can't resist to any infections. Avitaminosis can be shown differently, for example weakness, that is without any physical or intellectual activities.
As to avoid it
To any human body, and in particular children's, the daily need for vegetables is necessary. Becomes winter of a fresh vegetables much less and there is a need to compensate for the deficiency.
Earlier, when there was no such abundance of various dietary supplements and other medicines, people managed, and successfully, the vegetables prepared for the future. Various vegetables, fruit and mushrooms salted, dried, made sour and pickled. The fresh vegetables prepared for the winter practically doesn't lose the useful properties. Very few people know, but in sauerkraut contains vitamin C not less than in a citrus. And daily consumption of sauerkraut during the winter and spring period completely will fill the shortage of vitamin C and many other vitamins.
It is necessary to diversify a diet, adding various salads from root crops, cabbage, greens and at the same time to use all variety of the prepared preservation. It is a lot of recipes of salads from cabbage and radish there is on the Internet, their advantage in making tasty healthy food. The solid cellulose which is contained in these raw vegetables very positively influences processes of digestion and a vermicular movement of intestines.
Conclusion
If to use daily vegetables, then organism resilience to any viruses and infections will increase. Recipes of useful salads on the Internet and methods of preparation of vegetables will help you not to be left in the winter without useful products in enough.