The Good D
October 27, 2008
Vitamin D is one of the only vitamin produced naturally by the body, but production is dependent on exposure to adequate amounts of sunlight; an hour per week is reported to be sufficient. It is a fat-soluble vitamin, which can be dissolved and stored by the body. Forms differ depending on their source; from animals it is known as D2, or ergocalciferol; while D3 or cholecalciferol is the form obtained from animals. Whatever the source, vitamin D is critical to a number of human systems, and is therefore vital to health and wellbeing.
BENEFITS
Vitamin D regulates blood calcium and phosphorous levels, as it promotes their absorption from intestinal food, and in the case of calcium, its re-absorption in the kidneys. Calcium being essential to growth, health, and maintenance of joints and bones; its deficiency results in brittle bones, hypocalcaemia, and at its most severe, osteomalacia, that is, the softening of bones, due to abnormal bone mineralization. In this role, therefore, Vitamin D is paramount to the prevention of osteoporosis and joint pain. Further, the vitamin has been proven to slow the effects of arthritis, and reduce back pain, since the prevalence of joint degeneration is curtailed.
Vitamin D, like vitamin C, boosts the strength of the immune system, as it promotes phagocytosis, anti-tumor activity, and stimulatory and suppressive functions. Additionally, vitamin D controls the activation of the vitamin D receptor (VDR), a nuclear receptor and DNA transcription factor, which results in the regulation of gene expression associated with autoimmune diseases, and cancers. The vitamin also regulates cell growth and duplication, which, if left uncontrolled, lead to cancer growths. In fact, research links vitamin D deficiency to increased prevalence of prostate, colon and breast cancer.
Cellular differentiation, and proliferation inhibition are two other important, and required functions of vitamin D. Differentiation results in cell specialisation for specific bodily functions; differentiation of cells being necessary in limiting cell proliferation. Although proliferation is essential to growth, and wound healing, in excess, it leads to diseases such as cancer.
INTAKE
For males aged fourteen to fifty, the recommended daily intake (RDI) of vitamin D, is five micrograms, for those aged fifty-one to seventy, the RDI is ten micrograms per day, and those ages over seventy, the RDI is fifteen micrograms.
CONCLUSION
Vitamin D, as part of a healthy well-balanced diet, ensures the body’s health, as well as physical and emotional wellbeing. Sources such as fish are plentiful, and sunlight is readily available, making vitamin D quite easy to obtain.


























