Thursday, May 5, 2011

The Vitamin D Debate

Vitamin D has been a hot topic the past few years.

Some of the roles Vitamin D plays include: 

  • Bone health = works with calcium to help form bone, and aids with calcium absorption 
  • Helps reduce inflammation = which is associated with various other disease states and health, namely health health 
  • Improves muscle strength and function
Diseases states Vitamin D is associated with: 

  • Cancer:  Specifically 
    • Prostate
    • Colorectal
    • Breast
    • Ovarian
    • Esophageal
    • Non-Hodgkins lymphoma 
    • Why Vitamin D is responsible for gene regulation- AKA when a cell replicated and divides. A cancer tumor is caused by a rapidly dividing cell that is not properly regulated. Adequate Vitamin D status helps to prevent these regulation issues. 
  • Multiple Sclerosis  (MS) 
    • MS is a genetic, autoimmune disease that affects the central nervous system. There are 6 genes associated with the development of this disorder. Research has shown that adequate Vitamin D  status can either turn on or off these genes. Unfortunately- this likely occurs in fetal development to early childhood. So, if MS runs in the family it is especially important to have adequate vitamin D status during pregnancy and early childhood. 
  • Diabetes and Insulin Resistance 
  • Heart Disease (Cardiovascular disease) 

The main source is the sun, however, in the winter the sun is too far away from the Earth, especially for people in the northern hemisphere, so even if it is sunny out we cannot make vitamin D. 

Food sources are limited and highly variable some natural sources include: fish and mushrooms - but it varies by species, if they are wild or farmed and when they are picked/ caught and storage. 

Some foods are fortified, namely dairy products, cereals, and some orange juice. 

How much we need?: 
This is the hotly debated topic.  The current Institute of Medicine (IOM) recommendation is 600 IU for adults, and 800 IU for geriatrics. This recommendation is solely based on bone health as there is still much debate over the other areas that Vitamin D. 

Dr. Hollick is a strong advocate of Vitamin D and generally suggests 1,000- 2,000 IU a day for adults and children. 

The Vitamin D Council  recommend 5,000 IU a day for adults. 

So whats the deal?? Through the research I have reviewed- a fair bet for most adults and children is about 1,000- 2,000 IU a day. If an individual is deficient - it can take much more (50,000 IU / once a week for 12 weeks on top of 1,000- 2,000 a day) in order to have an adequate vitamin D status. 

Due to all of the new research out there relating vitamin D to so many disease states, many doctors are now testing vitamin D levels (Of course, to add to the confusion - there is also some debate over what is an adequate blood level.) Many medical facilities state that less than 30 ng/dL is low, whereas others state less than 40 or 50 is low. So, if you do get your levels checked, and they are below any of those numbers you may want to consider supplementing a higher dose. 

I used to be somewhat opposed to supplements and believe that you can get all of your nutrients in through a good diet - but honestly- vitamin D is NOT in most foods- so supplementing is necessary. 

My personal recommendation is to take at least 1,000- 2,000 IU/ day. If you wish to do a calcium and vitamin D supplement, make sure it has at least 500 IU of vitamin D per a pill, and take 2 a day (at separate times of the day for the calcium to absorb). If you decide to take a multivitamin, try to get at least 800 IU in the vitamin- there are few multivitamins out there with a higher dosage than that, which is why I think the easiest is to just get a separate 1,000 IU vitamin D supplement.  

D2 versus D3??? It doesn't matter, unless you have kidney failure. D2 is inactive, D3 is active. If you are healthy and take the inactive version, your body will convert it. 

DO NOT TAKE OVER 10,000 IU/ day unless prescribed by a doctor!! It is a vitamin- and can become toxic in excess
You cannot get a toxic amount of vitamin D from the Sun. Your body will not synthesize it.