Vitamin D And Breast Cancer Survival

Metabolites of Vitamin D are apparently able to increase the communication between cells by switching on a protein that blocks aggressive cell division. As long as vitamin D receptors are present, tumor growth will be prevented. Vitamin D receptors are lost once a tumor is very advanced. This is thought to be the reason for better survival in breast cancer patients whose vitamin D blood levels are high.
Dr. Cedric F. Garland, a PhD professor in the Department of Family and Preventative Medicine, had previously showed that low vitamin D levels were linked to a high rate of premenopausal breast cancer. This led him to explore the relationship between vitamin D and breast cancer survival rates.

Garland and his colleagues performed a statistical analysis of five studies of 25-hydroxyvitamin D obtained at the time of patient diagnosis and their follow-up for an average of nine years. Combined, the studies looked at over 4000 breast cancer patients.

Women in the high serum group had an average level of 75 nmol/L of 25-hydroxyvitamin D in their blood. The low group averaged just over 40 nmol/L.  The average level in all patients with breast cancer in the United States is 42 nmol/L.  The recommended “normal” range is 75 – 150 nmol/L.

You are able to have your Vitamin D levels tested here in Kelowna at our local labs, but it is not covered by MSP as a screening test.  You would be asked to pay for this test which currently costs around $65.  Virtually all the adults I test through my office who are not supplementing with Vitamin D will have levels much lower than 75.

“There is no compelling reason to wait for further studies to incorporate vitamin D supplements into standard care regimens since a safe dose of vitamin D needed to achieve high serum levels (above 75 nmol/L) has already been established,” said Dr. Garland.

The group from San Diego was able to determine that a serumlevel of 125 nmol/L is associated with 50 percent lower risk of breast cancer. While there are some variations in absorption, people who consume 4,000 International Units (IU) per day of vitamin D from food or a supplement would be expected to reach a serum level of over 100 nmol/L.  However, it is important to measure your levels before substantially increasing vitamin D intake.  I personally had been supplementing with 4,000 IU per day of Vitamin D3 tablets for the last 3 years, and when I had my levels tested I was still at 55 nmol/L, well below the recommended minimum level of 75.  I just wasn’t absorbing the tablets properly.  I have since switched over to a liquid emulsion at 10,000 IU per day with much better results.  Dosages of up to 50,000 IU per day have been shown to be safe, and I have even read a recent study using up to 300,000 IU!  There are, of course, a multitude of other health benefits associated with Vitamin D aside from breast cancer survival, including improved immunity and reduced risk of dementia as well as osteoporosis.

According to the National Institutes of Health, the current recommended daily allowance for vitamin D is 600 IU for adults and 800 IU for people over 70 years old.  I feel these recommendations are far too conservative, so be sure to have your levels tested.