Calcium and Osteoporosis
Osteoporosis is one of the most prevalent diseases among the women nearing the stage of menopause. It is a condition characterized by a generalized loss of bone mass. Bone has two compartments- the outer, hard shell of cortical bone, and the inner, structural matrix of trabecular bone. Osteoporosis is classified into two types, namely, type 1 and type 2 osteoporosis.
Type 1 osteoporosis:
It is characterized by a rapid bone loss, primarily of trabecular bone. It is also called post menopausal osteoporosis and is found to occur during 50 to 70 years of age. This type of osteoporosis is found to affect mainly the wrist and spine bone. Women are more commonly affected than men. The primary causes include rapid loss of estrogen in women following the menopause and loss of testosterone in men with advancing age.
Type 2 osteoporosis:
It is also called senile osteoporosis and is characterized by gradual loss of both trabecular and cortical bone. It is found to affect both women and men belonging to the age group of seventy years and above. The primary causes include reduced calcium absorption, increased bone mineral loss, increased propensity to fall.
Factors affecting osteoporosis:
The main factors found to affect osteoporosis are heredity and nutrition. Age is the strongest predictor of bone density. Other factors include hormonal status, physical activity, body weight, smoking, alcohol and drugs.
- The cells that contribute to the growth of bones are found to be most active during the first twenty years of life, after which it declines slowly. Hence, the bone loses its density and strength with the advancement of age. Vitamin D is the essential vitamin taken from the sunlight that helps in the absorption of calcium. For the proper functioning of the bones to take place, both calcium and Vitamin D is very much essential. Studies in women have proved a reduction in the rate of fracture with the supplementation of Vitamin D. At any circumstances, the body will only try to regulate the blood calcium at the desired level. In order to accomplish this equilibrium, the calcium that is stored in the bone is mobilized in conditions of inadequate calcium intake. Thus the calcium level in the blood is always maintained at the expense of the calcium stored in the body.
- Sex is the next strong predictor of loss of bone density with aging. It is because of this reason that women tend to have more chance of being affected by osteoporosis when compared to men. Estrogen deficiency is the main reason of fractures in women. In order to overcome this condition, estrogen is provided as a prescription drug to prevent bone loss. Over exercise and extreme reduction of body weight also results in bone density loss in women. Men are also susceptible to reduction in bone density. Removal of testes in males has resulted in occurrence of fractures in men. The same effect is also observed in aged men who had lost the functional ability of their testes. This indicates the role of male hormones in the prevention of osteoporosis in men.
- Genetic factors also are found to influence the bone density thereby influencing the occurrence of osteoporosis. This could be proved by comparing the bone density of people belonging to different regions in the world. The black people have denser bones when compared to the white people. From this it is evident that the bone density is influenced by the genetic makeup to some extent. Although, the genetic makeup is found to be affected by environmental factors such as physical activity, calcium nutrition and so on.
- Osteoporosis is not the disease of a day or two. It is the disease occurring as a result of unhealthy life style of the individual. Persons who do not have a good posture are easily affected. Moreover, physical activity is one of the reasons to build up the calcium stores in the bone. In contrast excessive exercise and activity could also deplete the calcium stored in the bones. The combination of too slender body, severely restricted energy intake, extreme daily exercise and the absence of menstruation reliably predict bone loss.
- People who abuse alcohol often suffer from osteoporosis and experience more bone breaks than others. Several factors appear to be involved such as alcohol promotes fluid excretion that leads to excessive calcium losses in the urine, alcohol may upset the hormonal balance required for healthy bones, alcohol may also slow the formation of bones leading to lower bone density. Alcohol abuse also increases the risk of falling. The effect of caffeine in the development of osteoporosis may be deleterious only when calcium intake is low.
- Over nutrition may also lead to the onset of osteoporosis. The mechanism behind this process is that the calcium is excreted in the urine when excessive amounts of dietary protein are consumed. Deficient intake may result in the development of other deficiency symptoms. Hence an adequate intake of protein should be included in the diet.
- Low calcium intake is the major reason for osteoporosis. When adequate amounts of calcium are present in the blood then the bones are not disturbed to withdraw calcium that is stored in them. The calcium intake of an Indian is recommended by the Indian Council of Medical research as 400 mg per day. This could very well be achieved by the intake of milk, milk products, and green leafy vegetables and so on.
People who do not consume adequate amounts of calcium rich foods are advised to consume calcium in the form of supplements. Supplements are commonly used as a part of therapy for osteoporosis, along with gentle exercise and for women, estrogen replacement, but supplements should not be used as a substitute for estrogen. As a rule, women taking estrogen need no more calcium than the recommended daily allowances.
The problems that arise from the calcium supplementation are impaired iron status, accelerated calcium loss, urinary tract stones or kidney damage in the susceptible individuals, exposure to contaminants, vitamin D toxicity, excess blood calcium, development of milk alkali syndrome, nutrient interactions and drug interactions, constipation, bloating, and excess gas formation.