Introduction
   Blood contains normal calcium at a level from 2.18 to 2.63 millimoles per liter (i.e. 9-11 mg/dl). Out of this range, people are identified as calcium deficiency which is related to osteoporosis caused by many factors such as lack of protein, deficiency of vitamin C and D and low calcium diet.
   According to my report of nutrients, I am surprised at my deficiency of calcium and vitamin D. I usually focus on eating enough vegetables and fruits daily, but I do not care about my intake of calcium and vitamin D. In my personal view, I think I am young and strong now, so I do not need to worry about how much adequate calcium and vitamin D I absorb everyday. However, more and more females suffer from osteoporosis when they are quite young because they do not intake enough calcium and vitamin D daily. This is not a disease only old women have nowadays. Osteoporosis trends to happen increasingly to young people. It is not treated like a disease with some people because it will not have any symptom when someone has already had it. It will occur when someone gets fracture. The reason why I wanted to choose these two issues is because I have noticed that I always ignore them in my daily life. Taking in adequate calcium and vitamin D is quite significant for me to prevent osteoporosis when I am getting older. Actually, osteoporosis is a natural and unavoidable part of aging. Some medical experts believe that osteoporosis can be preventable at most. We can take a few steps to prevent and reduce the risk of future fractures. Low bone density will trigger fracture as well. Keeping a healthy body and a balanced diet is not that easy. Sometimes lack of physical activities will also put me in danger of osteoporosis.
   An estimated 1.5 million individuals suffer a bone disease-related fracture each year (Riggs and Melton 1995, Chrischilles et al. 1991). Bones in our body not only need nutrition from food, but also need physical activities to keep them fit. Doing exercises is very important for bone health. Physical activities will help the body and bones to absorb calcium and vitamin D very well. Nutrition and physical activity are interacting with each other. Bones support humans to walk and act. That means they are consuming every minute. The density of bones will be lower and lower if we do not intake enough calcium and vitamin D.
   My nutrient report shows that the intake of calcium and vitamin D is not up to standard. I think that I am in the pink because I do not have too many bad diet habits. I always intake enough fruits and vegetables in daily life. However, except that I do not eat adequate protein and minerals. In fact, I put myself in danger of osteoporosis. My bones cannot be supplied with adequate vitamin D that is important for absorption of calcium. It will be get by exposure to sunlight through skin. A little food contains significant amount of vitamin D, such as fatty fish and fish oil. Milk and cereals are fortified with vitamin D. Although many people obtain adequate vitamin D and calcium naturally, they still need  to do exercises to help bones absorb nutrition.

Mechanisms
   Calcium is deposited mainly in bones and teeth. 99% of the calcium supports body movements and chewing ability. The other 1% existing in blood, tissues and organs is called blood calcium. The daily diet of most people accounts for about 90% of grains and vegetables. Cereal contains large amount of phytic acid preventing calcium absorption.
   In order to get more calcium, I try to eat many things such as tamarind cake, milk, yogurt, cheese, loach, mussels, screw, small shrimp, dried small shrimps, kelp, crisp fish, oysters, peanut, sesame paste, bean curd, pine seed, cabbage, broccoli, cabbage, rape and so on.
   Doing more sports can make my muscle powerful, to strengthen stimulus of bones, adjust the blood circulation and metabolism, reduce calcium loss, delay bone aging. At the same time, it will help my body to absorb dietary calcium.
   Sunshine (ultraviolet ray) can promote the absorption of calcium in the body. But ultraviolet ray can't penetrate glass, so I never lose any chance to be bathed in the open air.
   I eat a good breakfast. But more vegetables affect the absorption of calcium. Therefore, when I cook, I remove water from those such as cabbage, broccoli, spinach, amaranth, water spinach, mustard, pickled cabbage and bamboo shoots.
Vitmin D is the ramification of sterols, resistant to rickets and also called vitamin of rickets. Plants do not contain vitamin D which is fat-soluble, but it exists in the body and in part of the natural food. In ultraviolet irradiation, the cholesterol can be converted into vitamin D in the human body.
   Outdoor activities help me to accept enough sunlight. The body can synthesize enough vitamin D which is little in the natural food. Animals are the main sources of natural vitamin D, such as fatty fish, eggs, animal liver, egg yolk, cream and cheese. Lean meat contains microscale amount of vitamin D, so do milk, nuts, fruits, vegetables and grains.
   I eat canned salmon and trout, canned tuna and eggs fried or boiled.

Solutions and recommendations
   I don’t know if I lack calcium but sometimes feel obviously leg-soft, cramping, tired and easy to catch a cold. Lack of power causes me to try to  concentrate.
   Generally, young females, being nervous, have heavy stress. Quick rhythm of life often makes us neglect some of the physical discomfort. Deficiency of calcium and no typical symptoms are easy to hide our diseases. When there are frequent burnout, fatigue, cramps and sour backache, deficiency of calcium should be suspected.
    Checked in the hospital, I know what has happened to me.
   There are various reasons for me to come down. I seldom move, thus losing the weight of bones and weakening mechanical stimulation that can cause muscle atrophy, the bone formation to enhance the role of osteoporosis.
    If we lack sunlight, we can’t get vitamin D as we need. Cholesterol in human skin through ultraviolet rays can be transformed into vitamin D, which is the main source. Therefore, outdoor activity is quite important to me.
Conclusion
   National surveys suggest that the average calcium intake of individuals is far below the levels recommended for optimal bone health (Wright et al. 2003.). Therefore, citizens had better know more about themselves and follow their experts to have scientific diet.
   Measurements of vitamin D in nursing home residents, hospitalized patients, and adults with hip fractures suggest a high prevalence of insufficiency (Webb et al.1990, LeBoff et al. 1999, Thomas et al. 1998). As a result, we have to live in accordance with the Great Nature. As it is said, ‘Where there is readiness, there is no harm.’ Surely, everybody will become old. If I take care of myself since youth, my risk will be less and later.