This might be my most important newsletter to date as I believe that vitamin D can have the greatest impact on your health and at a price affordable to anyone. Vitamin D deficiencies are epidemic, and the benefits of optimal levels go far beyond simply bone health. Read on to find out the amazing benefits of vitamin D, how to obtain it, what blood levels are recommended and how it can be tested.
Vitamin D Statistics. An estimated 40-75% of the world’s population is vitamin D deficient (GrassrootsHealth). Even in southern climates, 55% of African Americans and 22% of Caucasians are deficient. The reasons are many including reduced sun exposure due to indoor jobs, use of sun block, skin color, and more. Some common signs of vitamin D deficiency include stiffness, muscle cramps, bone pain, balance and gait issues (i.e. clumsiness), low back pain, poor wound healing, depression, migraines and allergies.
The Benefits of Vitamin D. Thanks to 257 epidemiological studies, 2500 laboratory studies and some significant clinical trials(1) most experts on the topic of vitamin D feel it not only helps us maintain healthy bones, but that it can significantly reduce the incidence of a wide range of cancers (breast, ovarian, colon, lymphoma, kidney, endometrial), type 1 diabetes, multiple sclerosis, psoriasis, inflammatory bowel disease, depression, high blood pressure, seasonal affective disorder and heart attacks. The following is a summary of studies which shows the striking correlations between specific vitamin D blood levels and the percentages of reduced risk of incidence of a range of common life threatening chronic diseases:
• At 95 nmol/L, all cancers
• At 125 nmol/L breast cancers by 83%
• At 130 nmol/L Type I Diabetes by 66%
• At 135 nmol/L Multiple Sclerosis by 54%
• At 85 nmol/L Heart Attacks by 30%
• At 105 nmol/L Colon Cancer by 60%
• At 75 nmol/L Incidence of falls in women by 75%
• At 110 nmol/L fractures by 50%
• At 45 nmol rickets by 99%
You will notice that blood levels around 120 nmol/L appear to be highly protective against many common cancers and other life threatening diseases. All these percentages reference a common baseline of 62 nmol/L. In my clinical experience most people’s blood levels are far below 100 nmol/L. (1)
More than a Vitamin. In reality we now know that so-called vitamin D is really a steroid hormone and that it can affect the expression of our DNA which is how it is believed to alter the risks of cancer and other diseases. For those interested in the details, vitamin D affects the transcription of a number of genes and consequently can contribute towards apoptosis (the death of a damaged cell) as well as prevent cellular proliferation (that means cell growth and division) in cells of many lineages. (www.ncbi.nlm.nih.gov/pubmed/21371954)
Sources of Vitamin D. I’m often asked if we can get sufficient vitamin D levels from foods and the answer quite frankly no. Having said that, the best sources are shitake mushrooms, egg yolks, cod liver oil, and wild salmon. Fortified milk is not a good source due to the use of a poorly assimilated form of vitamin D (unless you plan on drinking 100 glasses a day!). From these foods you can derive a maximum of 1,000 iu vitamin D daily. Most of our vitamin D needs are meant to be obtained from exposure to sunlight and therefore for most of us this is the only way, other than by supplementing, that we can obtain the amounts necessary to obtain blood levels up in the 100 nmol/L mark. For the most part, only outdoor workers can obtain levels up to 150-200 nmol/L by the end of the summer. Here are some facts about sunlight:
• In Toronto we only produce significant vitamin D from sunlight exposure from April 15th to September 30th
• SPF 15 sunscreen blocks production of vitamin D by 99%
• A UV index greater than 4 is necessary to make vitamin D
• A light skinned person in a bathing suite makes up to 15,000 IU vitamin D in 15-20 minutes in July at midday
• Darker skin requires up to 7x more sunlight exposure to make the same amount as lighter skin
• If your shadow is taller than you are then you cannot make vitamin D
• You can get vitamin D from reflected light while sitting in the shade but not through a glass window (2)
Testing Vitamin D Levels. Sadly, effective December 1, 2010, OHIP stopped routine testing of vitamin D. I believe that if vitamin D supplements were a patented drug where money was to be made, pharmaceutical pressures would ensure it remained a routine screen. You can still pay to do a vitamin D test and I highly recommend this small investment. It costs $39 through a lab I use to give you a general idea. However, if you have one of the following conditions and/or circumstances, you can qualify for an OHIP covered test: Osteoporosis, Rickets, Osteopenia, Malabsorption Syndromes, Renal disease and regular use of drugs affecting vitamin D metabolism. Don’t assume your doctor is aware of all the circumstances under which you might qualify nor that he/she will automatically do this test if you do qualify. Do your research by going to the following link: http://www.hc-sc.gc.ca/fn-an/nutrition/vitamin/vita-d-eng.php. If you are a female and menopausal you might qualify to get free vitamin D testing through a local study currently being done on breast cancer prevention. For more information please go to www.grassrootshealth.net or email firstname.lastname@example.org
What are Optimal Blood Ranges of Vitamin D? According to Health Canada vitamin D deficiency is defined by serum levels below 25 nmol/L. This level is based on prevention of rickets and osteomalacia (both diseases of the bones). According to Dr. Reinhold Vieth, PhD, even at 50 mmol/L blood levels, 25% of the adult population still has osteomalacia (adult rickets). Even OHIP guidelines describe this threshold as “conservative”. (3) At a vitamin D symposium held at the University of Toronto on November 1st 2011 in Toronto, the entire panel of experts were unanimous in their opinion that these levels are too low and ignore the many epidemiological studies that suggest that higher levels can provide protection beyond simply preventing bone fractures.(4) In a time when cancer strikes one in two men and one in three women this conservative approach in my opinion is preposterous.(5)
How Much Vitamin D Is Enough? Health Canada recommended intakes are again based on the extremely conservative approach based on a goal simply to prevent frank bone disease and therefore they recommend only 600 iu for most adults.(6) My opinion is that optimal intake should be based on the following: (1) blood tests results, (2) individual response to supplementation (assimilation levels can vary widely so), and, (3) whatever levels are required to safely increase blood levels past the 100 nmol/L mark. Do not assume because you vacation to sunny places a few times a year that your levels are fine. Always rely on a blood test. Vitamin D supplementation should be supervised if exceeding the RDA in order to monitor individual responses and to ensure, although highly unlikely, no toxicity occurs. This can be prevented by testing periodically, and including important markers of toxicity such as ionized calcium levels and parathyroid hormone markers. In my experience, as well as that of many other clinicians’, one can generally dose significantly higher than the RDA for longs periods of time without any adverse affects.
Vitamin D Supplements. Because vitamin D is fat soluble, you can significantly increase your absorption of vitamin D if taken with a large meal that contains fat. For example, if you use olive oil in your salad or are taking fish oil supplements with your meal, this will suffice. Some vitamin D supplements are in an emulsified form which enhances their absorption and may be recommended for those with poor assimilation. I prefer vitamin D in the form of gel caps (in its own base of fat), liquids and/or sprays. Vitamin D tablets will likely be the least well absorbed, especially if taken on an empty stomach. Vitamin D can be taken daily or periodically, depending on the person and their needs. Most multivitamins do not contain enough vitamin D to meet daily requirements and/or to replenish deficiencies.
(2)Robbert Banner, MD, President, Ontario Society of Physicians for Complementary Medicine.
(4)Vitamin D Symposium November 1st 2011 Toronto (speakers Dr. Heaney, MD, Dr. Sorenson, EdD, Dr. Vieth, Ph.D, Dr. Banner, MD, Carole Baggerly)
This article was written by naturopathic doctor Thalia Charney who practises naturopathic medicine, homeopathy, nutrition, acupuncture, herbal medicine, intravenous therapy and mesotherapy in Toronto.