Vitamin D

Vitamin D is a steroid precursor. A deficiency plays a role in at least seventeen types of cancer, especially breast, prostate, and colon, as well as depression, and arthritis.

Vitamin D is synthesized in the skin but the trend to avoid the sun and the use of sunscreens limits the vitamin D an individual will actually produce. 

Ironically, melanoma, the deadliest form of skin cancer, is believed by some experts to be caused by sunlight/vitamin D and omega 3 deficiencies.

Other conditions associated with a lack of Vitamin D:

• Obesity
• Diabetes
• Osteoporosis
• Hypertension
• Heart Disease
• Autoimmune disorders
• Seasonal Affective Disorder
• Cold and flu

The upper limit for vitamin D in Canada is 4,000 IU for adults but some people need more initially.  We suggest healthy adults take 4,000 IU in the winter and 1,000 IU in the summer with time spent outside sans sunscreen!  People with existing health conditions should have their levels checked. The optimum range is 100-250 nanomoles/ml. 

“Because vitamin D is so cheap and so clearly reduces all-cause mortality, I can say this with great certainty: Vitamin D represents the single most cost effective medical intervention in the United States”. 

- Dr Greg Plotnikoff, Medical Director, Abbot Northwestern Hospital, Minneapolis        

Health Canada Upper Limits For Vitamin D

• Infants 0 – 6 months - 1,000 IU daily
• Infants 7 – 12 months - 1,500 IU daily – this dosage can be achieved by alternating 1,000 and 2,000 every 2nd day
• Children 1-3 - 2,500 IU daily – this dosage can be achieved by alternating 2,000 and 3,000 every 2nd day
• Children 4-8 - 3,000 IU daily
• Children and adults 9-70 - 4,000 IU daily

Anyone who suffers from inflammation or chronic disease should have their levels checked.  Some people may require much higher levels for several months before reaching optimum levels. 

Note:  The upper limit for our southern neighbours is 5,000 IU though they live in a sunnier clime than we Canadians!

*Revised February 2023