Several large studies have shown that people that had low vitamin D levels were twice as likely to have a stroke, heart attack, or other heart-related event during follow-up, compared to the people that had higher levels of vitamin D. Researcher James H. O’Keefe, M.D. and director of preventative cardiology at the Mid America Heart Institute in Kansas City, MO., stated, “Vitamin D deficiency is an unrecognized, emerging cardiovascular risk factor, which should be screened for and treated. Vitamin D is easy to assess, and supplementation is simple, safe and inexpensive.”
The skin, in response to exposure to the sun, meets most of the body’s requirements for vitamin D. Other less potent sources of vitamin D include foods such as cod liver oil, sardines, and salmon. Also, vitamin D can also be found in D-fortified foods milk and some cereals. If you do not get enough vitamin D you can also take vitamin D supplements on a daily basis.
A deficiency of vitamin D is traditionally associated with muscle and bone weakness, but in recent years a number of studies have shown that the low levels of vitamin D may predispose the body to congestive heart failure, blood pressure, and chronic blood vessel inflammation (which is associated with the hardening of the arteries). It can also alter hormone levels, which will increase insulin resistance, which can raise the risk of diabetes.
In an article that was published in the Journal of the American College of Cardiology, the researchers surveyed recent studies on the link between heart disease and vitamin D deficiency to come up with some practical advice on screening and treatment. They also concluded that the vitamin D deficiency is much more common that they previously thought, and could be affecting up to half of adults and children in the United States.
The researchers say that higher rates of vitamin D deficiency could be due in part to people spending more time indoors and in the effort to reduce sun exposure through the use of sunscreens. If you use a sunscreen that has a sun protection factor (SPF) of 15, you should know that it blocks nearly 99% of vitamin D synthesis by our skin.
Americans are spending less time outside now than previous generations, and older adults and people that are obese or overweight are less efficient at making vitamin D when exposed to sunlight. A little bit of sunshine each day is good, but the use of sunscreen to protect against skin cancer is important if you plan out staying outside for more than 15 to 30 minutes of intense sunlight exposure.
You can find out what your vitamin D levels are via a blood test that looks at a specific form of vitamin D called 25-hydroxy vitamin D (25(OH)D). A deficiency of vitamin d can be defined as a blood 25(OH)D level of below 20 ng/dL. A normal level is considered to be above 30 ng/dL.
The researchers recommend a 25(OH)D screening for that that have known risk factors for a deficiency of vitamin D including:
• Reduced exposure to the sun due to variation or by living far away from the equator
• Old age
• Liver or kidney disease
• Skin that is darkly pigmented
The government’s current recommendation daily allowance (RDA) for vitamin D is 200 international units (IU) daily for individuals that are under the age of 50. For those that are between 50 and 70, it is recommended to take 400 IU daily, and for those that are over the age of 70, the RDA is 600 IU. Most experts believe that these recommended does are still too low, and that somewhere between 1,000 and 2,000 IU of vitamin D daily is necessary to maintain adequate levels of vitamin D. The upper limit of vitamin D that is safe to take on a daily basis is 10,000 IU.
Vitamin D supplements are available now in two different forms: Vitamin D3 and Vitamin D2. Although both types appear to be effective in raising the levels of vitamin D, Vitamin D3 supplements appear to result in a boost in the levels of vitamin D that is longer-lasting. However, there are no current guidelines for restoring and maintaining a healthy level of vitamin D in people that are at risk for heart disease, for those that are vitamin D deficient, the researchers recommend an initial treatment with 50,000 IU of vitamin D2 or D3 once weekly for eight to 12 weeks, that is followed by maintenance with one of the following strategies:
• 50,000 IU vitamin D2 or D3 bi-weekly
• 1,000 to 2,000 IU of vitamin D3 every day
• Sunlight exposure for at least 10 minutes for white patients (longer for people that have increase skin pigmentation) between the hours of 10 a.m. and 3 p.m.
Once the maintenance therapy has been initiated, rechecking 25(OH)D blood levels is highly recommended after three to six months of ongoing supplementation.
O’Keefe stated, “Restoring vitamin D levels to normal is important in maintaining good musculoskeletal health, and it may also improve heart health and prognosis. We need large, randomized, controlled trials to determine whether or not vitamin D supplementation can actually reduce future heart disease and deaths.”