Skin becomes dry because it lacks moisture from within or because substances that normally retain moisture are lacking. The skin cells need water and this nutrient is continually lost from the surface of the skin. Water loss is greatest during winter when cold winds, low humidity, and dry indoor heating increases evaporation from the skin.
Coffee, black tea, and alcoholic beverages contain diuretics that move water out of the cells and encourage water loss and dryness. These beverages should not be included in the recommended 6 to 8 glasses of fluids consumed each day.
People who are physically active need more water to replace losses from perspiration. Perspiring promotes moist skin by stimulating tiny glands that keep the skin coated with natural oils. Regular physical activity and drinking water maintain moist, healthy skin.
Fat in the hair diet is another important nutrient for moist skin. The polyunsaturated fats in vegetable oils contribute to the natural oils of the skin. Women and teenage girls who are on strict hair diets might not consume enough fat. Older adults who live on a lowr calorie hair diet might not consume ample amounts of fat in the hair diet. If the hair diet is very low in fat, add a tablespoon of vegetable oil to the daily salad. Safflower and sunflower oils are the best sources of polyunsaturated oils. Soy and corn oils also are good choices. Nuts, seeds, soft margarines, and avocado provide good sources of fat. These fatty foods are only to be advised for those people wTho consume less than 15% of their calories as fat. Chronic or severe hair dieting, cigarettes, and alcohol can increase the likelihood for nutrient deficiencies and might result in dry skin or dandruff.
The fat-soluble vitamins A and E are not absorbed unless some fat is available in the hair diet. These nutrients are essential for healthy, moist skin. If the skin becomes dry at a particular time of the year, such as in the winter, foods high in vitamins A and E should be increased to at least two servings a day.
The water-soluble vitamins also are important to maintain moist, subtle skin. These include vitamin Bj, vitamin B2, niacin, pantothenic acid, vitamin B6, folic acid, vitamin B12, and biotin. Vitamin C helps the oil-secreting glands function properly. Without enough vitamin C, the skin does not make adequate amounts of the natural oil coating of the skin to keep the skin from drying out. Since many factors increase the need for vitamin C, such as smoking, oral contraceptives, and stress, include two or more servings a day of vitamin C-rich foods in the hair diet. (See page 39 for hair dietary sources of vitamin C.)