IV] Role of Vitamin D in Cancer

As of this day, a clear association between Hypovitaminosis D and colon Cancer has been established. Lower the Vitamin D levels, higher the risk of developing colon cancer. Garland et al. Have clearly concluded from their clinical trials that “Intake of 2000 IU/day of Vitamin D3, and, when possible, very moderate exposure to sunlight, could raise serum 25(OH)D to 52 ng/ml, a level associated with reduction by 50% in incidence of breast cancer, according to observational studies.” Lappe in a randomised controlled trial has studied the reduction in cancer risk in postmenopausal women taking vitamin D and calcium supplementation. He has concluded that there is a definite reduction in the all-cancer risk in such ladies receiving calcium and vitamin D supplementation. The cancers
specifically studied under this trial were breast, colon, lung cancers and marrow/lymphoma.

V] Role of Vitamin D in Diabetes Mellitus

Observational studies have established the fact that vitamin D supplementation in early childhood had reduced the incidence of Type 1 diabetes mellitus. However these results are yet to be corroborated by randomised controlled trials. Inadequate vitamin D levels, insufficient exposure to the ultraviolet rays of the sun and low dietary intake of vitamin D have each been associated with an increased risk for the development of Type 1 diabetes mellitus. Hypovitaminosis D also leads to development of insulin resistance, which also indicates its association with Type 2 diabetes mellitus. Moreover, the risk of developing cardiovascular complications secondary to diabetes is also raised as a result of vitamin D deficiency. On the positive side, Vitamin D supplementation in patients having diabetes reduces the risk of having any major complication of the same.

VI] Role Vitamin D in Psoriasis.

Psoriasis is an autoimmune disease primarily affecting the skin. Vitamin D supplementation has shown very promising results in the treatment of Psoriasis.

VII] Role of Vitamin D in respiratory infections.

Vitamin D has been known to provide better immunity against respiratory infections. Children having rickets were found to be more likely to have a common cold and other respiratory infection. In adults with Vitamin D deficiency, the occurrence of common cold was found to be significantly higher. On the other hand, the incidence of Influenza A was found to be reduced significantly in individuals having adequate Vitamin D levels either naturally or those receiving Vitamin D supplements. The role of Vitamin D deficiency in development of tuberculosis is currently under study and the results of the trials are awaited.

VIII] VitaminD and the Geriatric Population

As we have already seen above, Vitamin D is essential for normal mineralisation of bones and maintenance of their strength. In old aged individuals, osteoporosis is more common and hence the bones are already softer than normal. This coupled with the fact that there may be many co-existent co-morbidities leads to higher chance of fractures. Falls are common in old age and are the most common cause of fractures. Vitamin D deficiency has been shown to increase the risk of falls as well as increase the risk of suffering fractures as a result of the falls. In the geriatric age group, a fall can have devastating results. The most common fracture suffered as a result of falls in the old age is the fracture of the neck of the femur. This fracture is notorious for the fact that the mortality rates of old persons having suffered a fracture neck femur are significantly higher than those who have not.


Hypervitaminosis D

Sometimes as a result of excessive intake of Vitamin D supplements, people have elevated levels of Vitamin D. The exact value over which vitamin D toxicity manifests is still debatable but values over 100 ng/ml are definitely worrisome. An excess amount of vitamin D in the blood stream causes raised serum calcium levels. This translates into over calcification of bones and soft tissues. It may cause formation renal calculi subsequently leading to renal damage. The cardiovascular system is also prone for damage from hypocalcaemia resulting from raised serum vitamin D levels

The clinical signs and symptoms of hypervitaminosis D are

  1. vomiting,
  2. dehydration,
  3. constipation,
  4. muscle weakness,
  5. myalgia and mental irritability.