Vitamin A: If taken on an empty stomach, vitamins will be excreted in feces before the body can absorb and utilize them. Fat-soluble vitamins, such as vitamin A, must dissolve in fat to be absorbed by the gastrointestinal mucosa. Therefore, they should be taken after meals to ensure more complete absorption.
The epithelial cells of the elderly are easily damaged, and their resistance is relatively low. Vitamin A's main function is to maintain the growth of various epithelial cells; therefore, appropriate vitamin A supplementation is necessary. In addition to obtaining some from food (such as carrots, dairy products, eggs, animal liver, dark green vegetables, and dairy products), vitamin A capsules can be taken separately, one capsule once daily, containing 25,000 IU, intermittently.
Vitamin C: This is an extremely delicate water-soluble vitamin. Its properties are very unstable, and it is easily destroyed by oxidation. The human body cannot synthesize vitamin C and must obtain it from food. Therefore, care must be taken when consuming and cooking vitamin C. Vitamin C is susceptible to damage from water, heat, light, oxygen, and smoke. Soaking in water, cooking, or direct sunlight can significantly destroy vitamin C. Furthermore, smoking a single cigarette depletes 25 mg of vitamin C, and consuming 100 mg of fried food also depletes 25 mg of vitamin C
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Vitamin E: An essential nutrient for the human body, many people regularly take vitamin E supplements. However, a recent study shows that the abuse of vitamin E is not only ineffective but also reduces lifespan and conflicts with cholesterol-lowering drugs.
Researchers at Tel Aviv University in Israel published a study in the latest issue of the American journal *Arteriosclerosis, Thrombosis & Vascular Biology* [7], tracking approximately 300,000 people from the United States, Europe, and Israel, comparing those who took vitamin E with those who did not. The results showed that the former had nearly four fewer quality-adjusted life years than the latter.
Which foods are rich in Vitamin E?
The so-called "quality-adjusted life year" (QLAC) converts the number of years of survival with different qualities of life into the equivalent number of years of survival in perfect health. It is a concept used to evaluate the degree of change in the quality and quantity of life brought about by treatment and health care. However, researchers point out that this does not mean that everyone who takes Vitamin E supplements will live four months less. Previous studies have also found that Vitamin E supplements not only do not prevent certain diseases, but may also conflict with cholesterol-lowering drugs. Researchers say that if sufficient Vitamin E can be obtained from food, supplementation is unnecessary.
Vitamin B6: Incorrectly taking high doses of pyridoxine (2-6g daily for 2-40 months) due to premenstrual stress can cause progressive sensory ataxia and severe impairment of lower limb positioning and vibration sensation, with little impact on touch, temperature, and pain sensation. The motor and central nervous systems are not damaged. Recovery after stopping pyridoxine is very slow, and some patients only recover partially. Anti-cancer vitamins are components of various tissues in the human body and do not provide energy. Excessive intake is not beneficial to the body, and some can even produce toxic side effects or death.