You need to pay extra attention to your vitamin and nutritional intake if you want to maintain good winter health.
While January and February's wind, rain, and snow can curtail many of our activities ... germs and viruses go right on about their business of making us sick regardless of the weather! In fact, it sometimes seems as if the invisible nuisances absolutely thrive during the wet, chilly months . . . "brewing up" an endless assortment of colds, coughs, sniffles, sore throats, and all of the other related miseries that accompany such illnesses.
Consider, though, that humankind's wintertime vulnerability to colds and flu may not lie so much with these malevolent microbes and virulent viruses (they're around much of the time anyway) as it does in the change of lifestyle that winter often brings.
We tend, for example, to spend more time indoors (all too often in hot, stuffy rooms) during the winter months, and—when we leave our closed-up and heated homes for the frigid outdoors—we give our systems a resounding shock. Then, once outside, we still have to contend with unexpected, drastic changes in the weather itself! Such winter stresses tend to use up the body's supply of vitamin C at a rapid rate. Yet fresh fruits and vegetables, our best source of C, are often so expensive and in such short supply during the cold part of the year that—more than likely—most folks actually reduce their intake of such important foods when they need them more than ever!
For optimum winter health, we need to give special consideration to our intake of the oil vitamins, A and D, too. Vitamin D (the "sunshine" vitamin) is present in only limited quantities in most ordinary foods ... with the exception of such "primary sources" as egg yolks, fortified milk products, and unrefined oils. If you spend considerable time indoors and avoid consuming milk and eggs (items that are often kept out of people's diets for any one of a number of reasons), your body may be short on D. (And, as you probably know, a vitamin A deficiency can lower your resistance to respiratory and other infections.)
During the winter months many people also seem to turn to sweeter and/or starchier diets. And—since more time is devoted to games, reading, and other indoor leisure pursuits during the cold part of the year—folks have a tendency to snack more.
Such impromptu eating habits can create, among other things, a deficiency in the minerals needed for the essential action of certain enzymes that break down and metabolize the nutritious foods we do eat. Furthermore, the older men and women get, the more they may have to rely on enzymes in their diets ... rather than the supply their bodies produce. However, enzymes are generally destroyed when they encounter any heat higher than body temperature, so—since we eat more cooked foods in winter—it's no wonder a "cold season" seems to occur during the chilly months.
Fortunately, all such essential nutrients —plus the equally vital protein, iron, and B-complex vitamins—can be easily obtained in a carefully planned winter diet ... or through the use of well-balanced vitamin and mineral supplements, which (if taken on a regular basis) can do a great deal to stave off or at least minimize the miseries that winter or a change in seasons often brings.