VITAMINS AND MINERALS
Vitamins are organic compounds that are essential in very small amounts for supporting normal physiologic function.
Vitamins fall into two categories: fat-soluble and water-soluble. The fat-soluble vitamins — A, D, E, and K — dissolve in fat and can be stored in your body. The water-soluble vitamins — C and the B-complex vitamins (such as vitamins B6, B12, niacin (vitamin B3), riboflavin (vitamin B2), and folic acid or folate (vitamin B9)) — need to dissolve in water before your body can absorb them. Because of this, your body can't store these vitamins. So you need a fresh supply of these vitamins every day.
Whereas vitamins are organic substances (made by plants or animals), minerals are inorganic elements that come from the soil and water and are absorbed by plants or eaten by animals. Your body needs larger amounts of some minerals (macro-elements), such as calcium, to grow and stay healthy. Other minerals like chromium, copper, iodine, iron, selenium, and zinc are called microelements because you only need very small amounts of them each day.
Vitamins and minerals are often called micronutrients because your body needs only tiny amounts of them. But lack of even those small quantities virtually guarantees disease. Here are a few examples of diseases that can result from vitamin deficiency:
- Scurvy. Old-time sailors learned that living for months without fresh fruits and vegetables – the main sources of vitamin C – causes the bleeding gums and weakness.
- Blindness. In some developing countries, people still become blind from vitamin A deficiency.
- Rickets. A deficiency in vitamin D can cause rickets, a condition marked by soft, weak bones that can lead to skeletal deformities.
Just as a lack of key micronutrients can cause substantial harm to your body, getting sufficient quantities can provide a substantial benefit. Some examples of these benefits:
- Strong bones. A combination of calcium, vitamin D, vitamin K, magnesium, and phosphorus protects your bones against fractures.
- Healthy teeth. The mineral fluoride not only helps bone formation but also prevent dental caries.
It is important to remember that vitamin and mineral deficiencies can negatively affect not only your physical capabilities but also your mental health. Deficiencies in a number of vitamins and minerals can lead to the symptoms of depression, paranoia, anxiety, fatigue, and tearfulness. But it is also important to remember that high doses of certain vitamins can cause vitamin poisoning.
STRESS
Stress is a psychological and physical response of the body to changing conditions. Small amounts of stress may be desired, beneficial, and even healthy. In most cases, stress promotes survival because it forces organisms to adapt to rapidly changing environmental conditions. Excessive amounts of stress may lead to bodily harm and can increase the risk of stroke, heart attacks, ulcers, and mental disorders such as depression.
Thus, there are two types of stress, eustress (good stress) and distress (negative stress). Eustress refers to the optimal amount of stress which helps promote health and growth. Distress is damaging, excessive or pathogenic (disease producing) stress.
Stress can, directly and indirectly, contribute to general or specific disorders of body and mind. Stress can have a major impact on the physical functioning of the human body. Stress raises the level of adrenaline and cortisol – so-called stress hormones - in the body, which in turn increases the heart rate, respiration, blood pressure and puts more physical stress on bodily organs.
Physiological response to stress is called the general adaptation syndrome. The general adaptation syndrome has three phases:
1) alarm reaction;
2) resistance;
3) either exhaustion or recovery.
Chronic stress is accompanied by cognitive, emotional, physical and behavioral symptoms.
- cognitive symptoms: memory problems, inability to concentrate, seeing only the negative, etc;
- emotional symptoms: moodiness, irritability, sense of loneliness and isolation, depression, etc;
- physical symptoms: chest pain, rapid heartbeat, nausea, dizziness, etc;
- behavioral symptoms: eating more or less, sleeping too much or too little, using alcohol to relax, etc.
Stress management can teach you healthier ways to cope with stress, help you reduce its harmful effects, and prevent stress in the future.
Дата добавления: 2016-09-06; просмотров: 1792;