reduce risk breast cancerThe most well researched supplement in the past 2-3 years might be vitamin D (and new research shows it may reduce the risk of breast cancer).

Testing has become widespread, supplementation is recommended by major governing bodies (including Health Canada!) and has been adopted by the conventional system.

With so much negative research coming out about vitamin E and calcium it is great to see a simple over-the-counter nutrient arrive on scene with major research supporting its use.

My interest in vitamin D has gone beyond its benefits for mood in the dark winters of Vancouver. It has been well researched for bone health and we are seeing great benefit when combined with K2 (a topic for another day) for strengthening bone – beyond traditional calcium use.

Currently my interest in vitamin D is in breast cancer prevention and during treatment to improve the effectiveness of conventional and integrative therapies. Since the 90’s (maybe earlier) we have known that there may be a correlation between low vitamin D levels and breast cancer.

Low Vitamin D Levels Associated with an Increased Risk of Breast Cancer

Recently the magnitude of risk has been discovered and the mechanisms for why it reduces risk have been published.

In the latest correlational study the details were clear:

“Researchers found a lower level of the vitamin D biomarker in women with advanced-stage tumors. The lowest levels were found in premenopausal women with triple-negative cancer.” – REF

This is such great news because it gives objective results and reasoning for use. Its benefits are tangible and the best part – levels are easy to test.

In cancer treatment there are a few in vitro studies that have been published recently showing its benefit in treatment. In genetic expression studies done on mice Vitamin D supplementation (reaching adequate levels) prevents the growth of breast cancer cells.

Overall, Vitamin D supplementation is still up for debate but there is reason to be keeping levels in the normal range during breast cancer treatment will improve outcomes.

How to Test Your Vitamin D Levels – and Reduce Your Risk of Breast Cancer

Maintaining a positive mood in the darker months, keeping bones strong, optimizing the immune system and now potentially reducing the rate of breast cancer means maintaining an adequate level of vitamin D is more important than eve.

Testing for vitamin D can be done through your Naturopathic or Family Doctor in Canada. The test is a simple blood spot test and the cost is approximately $75.

Testing is recommended every 6 months for those at high risk of deficiency.

Treatment of vitamin D deficiency is very simple. Health Canada is recommended 1000IU per day for all adults and 400IU for children.

According to recent trial on breast cancer prevention these numbers may be low (depending on your sun exposure and intake). Many fair skinned people can reach this level with 12 minutes of sunshine per day.

Much of our food is now fortified with vitamin D as well so that makes it easier to reach these levels.

Usually consuming 2000-3000IU per day for people living in British Columbia will keep their levels in the normal range. This is very easy with vitamin D drops. In my practice I use Vitamin D3 by Genestra. Each drop is 1000IU but many brands are developing this product now.

Please note – in osteoporosis we use D3 + K2 by Genestra.

Keeping vitamin D levels in the “normal” range has been shown to reduce breast cancer risk by 50-77% depending on the study you cite. Vitamin D is such an important nutrient for bone health, mood, hormone balance and energy levels it can’t be missed.

If you suspect your levels may be low check with your physician or naturopathic doctor today to have them tested. Results take 3-4 days to be produced and raising the levels to achieve sufficient levels is easy and quick.


Dr. David Duizer is a co-founder of and a Naturopathic Physician practicing in Vancouver, British Columbia. He is a passionate, driven, motivated leader in integrative medicine focused on optimal wellbeing, holistic healing and natural health.

To learn more about Dr. David Duizer Click Here. Connect with David on Twitter @davidduizer, Facebook, and Google+.

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