Question: My doctor says there is no point in testing vitamin D and that I should just take a 1000iu.
But some friends have had their vitamin D tested and it came back really low in spite of their 1000iu of D and then they needed to take more to reach ideal levels. What dose should I be taking to ensure my levels are ideal and why do some doctors test and others don’t? Do NDs test?
Answer: I feel that 2000-4000 iu of vitamin D3 is adequate for most adults. D3 should be taken with a meal that contains fat, because vitamin D is fat soluble and needs bile for absorption from your small intestine.
However, I have seen 2000iu per day be inadequate to reach an optimal level of 100nmol/L. There is resistance to vitamin D testing because of cost. Some say they are being responsible by not spending unnecessarily. Others believe that 1000iu is enough, and rarely it is, and that vitamin D screening is unnecessary. Some test because they are more yielding to patient requests, but do not suggest it. Then there are those who test because of the importance of establishing optimal levels and their experience or reading has shown that a one size fits all approach does not deliver.
NDs can order blood tests, but they have to be sent to Ontario and you have to pay. I think that as a taxpayer you should not need to do that. Unlike other blood tests we don’t feel vitamin D needs to be checked yearly and anywhere from one to three tests performed after you have been supplementing at least 2000iu per day for several months, preferably at the end of winter, will help establish a dose for you.
In January, the latest Statistics Canada Report on vitamin D revealed that the average vitamin D blood levels for Canadians between the ages of six and 79 years of age fell from 67.7 nmol/L in 2009 to just 63.5 nmol/L in 2011. This decrease is disturbing as research studies continue to show that people with lower vitamin D levels are at a much higher risk of developing serious diseases.
Only a third of Canadians supplement vitamin D — at what dose we are not sure because that was not stated. But whatever dose, it was not enough, and those aged 12-39 age had the lowest vitamin D levels.
There were 68 per cent of Canadians who had vitamin D blood levels sufficient for healthy bones at 50 nmol/L. However, fewer than 10 per cent of Canadians reached natural optimal levels of over 100 nmol/L — the amount associated with an overall decrease in disease incidence including heart disease, MS, Type I diabetes, depression and various cancers. Colorectal cancer is the second leading cause of cancer death. According to the National Cancer Institute, vitamin D levels of 80nmol/L or higher were associated with 72 per cent risk reduction on colorectal cancer mortality, based on the vitamin D levels of 16,818 participants over 12 years.
A study published in Molecular Nutrition & Food Research in 2010 reported that if all Canadians reached a vitamin D blood serum level of 105 nmol/L we could expect an annual reduction in health-care costs of $14.4 billion, which more than justifies testing costs. In fact, we would be hard pressed to think of any drug or supplement that has such a low cost benefit ratio.
Kali Simmonds, ND, is a doctor of naturopathic medicine who practices in Charlottetown. The information provided is not intended to diagnose or substitute the advice of a health-care professional. Consult with a health-care provider before making any changes. She welcomes questions for this column, which is published every second Tuesday in The Guardian. She can be reached by mail at 34 Queen St., Charlottetown, C1A 4A3 or by email at email@example.com.