Vitamin D – Importance of Vitamin D for Canadians
Vitamin D and Self Care
How much Vitamin D do I need? The answer to this question depends on a number of factors. Where you live impacts Vitamin D levels greatly. In the Tropics and sub tropics on a typical day a human body will make 20,000 units of Vitamin D in a day. If you get a sunburn your body will have made some 50,000 units of Vitamin D (based on minimal erythemal dose). If you live in the the tropics or subtropics you don’t need Vitamin D (unless you never go out into the sun and when you do, slather yourself with sun screen). Everyone in Canada (including Southwestern Ontario) live at a latitude where the suns rays from October to May, do not have enough energy to cause the changes which makes Vitamin D. Well what does Vitamin D do and is it important to maintain its level in the human body?
Vitamin D is also called ‘calciferol’. It is a fat soluble vitamin which is necessary for the formation of the skeleton, mineral (calcium) homeostasis and has an important role in the regulation of the immune system. Vitamin D has now been implicated to play an important role in multiple sclerosis and certain cancers. Vitamin D is produced when cholesterol circulating in serum just under the skin is exposed to ultraviolet light from the sun and is converted to 7-dehydrocholesterol which is then further converted to25-dehydroxycholecalciferol (25-VitD) in the liver and further converted to 1,25 dehydroxyvitamin D in the kidney. The action of the sun is the rate limiting step in this sequence of events; that is, no sun exposure with adequate uv light, no Vitamin D.
Vitamin D should actually be viewed as a type of hormone related to the steroid class of hormones.
Lack of vitamin D is associated with inadequate bone mineralization. This leads to rickets in children, almost unheard of today in its severest manifestation, in due mainly because of the fortification of foods with Vitamin D. In early industrialized England when steam engines spewed clouds of smoke into the skies above London causing a blocking out of the suns rays, rickets was a common disease among’s children. The bones become so weak that they ‘bow’ and fracture easily. The evolving story of Vitamin D in modern society has linked it with multiple sclerosis. (This may explain the observation that the incidence of MS is highest in northern countries such as Canada, Scotland and the Scandinavian countries.) As with many other diseases, low Vitamin D levels is associated with the genesis of MS, yet once the disease has developed, giving Vitamin D does not reverse the progression of the disease in studies thus far. Prevention is always more effective and easier than cure. Other studies have associated Vitamin D deficiency with risk of stroke. Children with low Vitamin D levels are more susceptible to lung infections and Diabetes Mellitus Type 1. Associations with low Vitamin D levels and certain cancers has been established. Research into the basic mechanisms of how Vitamin D helps in the regulation of the immune system is giving us insights into how lack of this hormone/vitamin may be involved in these diseases.
So how much Vitamin D is required for optimal functioning of the body? The best current information states that maintaining a blood level of 100 to 150 nmol/L is and optimal range. For most people taking between 1,000 IU and 2,000 IU of Vitamin D during the months when sun exposure does not produce this Vitamin will maintain these blood levels. The past recommendations of 400 IU of Vitamin D is simply not adequate.
For more information please see www.vitamindcouncil.com