|
|
|
|
|
 Vitamin D is the body’s primary regulator of calcium homeostasis. It aids with bone mineralization and skeletal development. Considered a prohormone, vitamin D does not have hormone activity, but can be changed into a molecule that does.
Vitamin D helps blood cell formation, immunity, and helps cells “differentiate,” which may lower cancer risks. Vitamin D has shown in human and animal studies to possibly provide protection from autoimmune arthritis, multiple sclerosis, and juvenile diabetes.
Vitamin D helps the body maintain necessary insulin blood levels. Vitamin D receptors are located in the pancreas, where insulin is produced. Supplementation might increase the secretion of insulin in those with type 2 diabetes.
Vitamin D has been used in those with the following health problems:
- Crohn’s Disease
- Cystic Fibrosis
- Osteoporosis
- Rickets/osteomalacia
The extent to which vitamin D can help reduce fractures and bone loss in the elderly is still not definite, however some evidence claims that it is useful. Vitamin C may limit or prevent perinatal growth retardation and may alleviate some forms of psoriasis. Researchers hope to find vitamin C to be beneficial to treat immunodulation, cancer, infertility, and diabetes. Early research is also showing the possibility of vitamin D being used to help seasonal depression, bilateral cochlear deafness, increase resistance to seizures, and help with multiple sclerosis and sick sinus syndrome.
Vitamin D Deficiency
Vitamin D deficiency in adults may cause osteomalacia, or the softening of the bones. This condition is usually treated with calcium supplements and vitamin D. Treatment for osteomalacia should be diagnosed and treated by a physician. Abnormal bone formation occurs in those with vitamin D deficiency. The deficiency is more common in the winter when access to sunlight is restricted. Deficiencies are also more common in highly polluted areas where ultraviolet rays from the sun can be blocked.
Strict vegetarians, alcoholics, those with kidney or liver disease, and dark-skinned people are more likely suffer from vitamin D deficiency. Those with kidney or liver disease do produce vitamin D but do not activate it.
People with intestinal malabsorption more commonly are vitamin D deficient. Those with insufficient pancreatic function such as cystic fibrosis or pancreatitis, or with hyperthyroidism such as Graves’ disease, are often vitamin D deficient.
Recommended Dosage
Vitamin D in supplement form can be obtained as vitamin D2 (ergocalciferol) or as vitamin D3 (cholecalciferol). Multivitamins generally contain vitamin D. Recommended dosage is 200-400 IU, or 5-10 micrograms, each day. 400 IU are found in multi-mineral, pre- and postnatal vitamins.
The elderly and those with malabsorption syndromes, hepatic failure, and nephritic syndrome receive supplements with 50,000 IU, or 1,250 micrograms, weekly for an eight week period. This should only be done under the supervision of a physician.
Supporting Literature
Hayes CE, Cantorna MT, Deluca HF. Vitamin D and multiple sclerosis. Proc Soc Exp Biol Med 1997;216:21–27.
Agarwal KS, Mughal MZ, Upadhyay P, et al. The impact of atmospheric pollution on vitamin D status of infants and toddlers in Delhi, India. Arch Dis Child 2002;87:111–113.
Chapuy MC, Preziosi P, Maamer M, et al. Prevalence of vitamin D insufficiency in an adult normal population. Osteoporos Int 1997;7:439–443.
Kyriakidou-Himonas M, Aloia JF, Yeh JK. Vitamin D supplementation in postmenopausal black women. J Clin Endocrinol Metab 1999;84:3988–3990.
Silverberg SL, Shane E, Dempster DW, Bilezikian JP. The effects of vitamin D insufficiency in patients with primary hyperparathyroidism. Am J Med 1999; 107:561–567.
Basha B, Rao S, Han ZH, Parfitt, AM. Osteomalacia due to vitamin D depletion: neglected consequence of intestinal malabsorption. Am J Med 2000;108:296–300.
Thomas MK, Lloyd-Jones DM, Thadhani RI, et al. Hypovitaminosis D in medical inpatients. N Engl J Med 1998;338:777–782.
|
|
|
