By Dr. Mercola
Vitamin D is crucial for good health, and may be one of the simplest solutions to a wide range of health problems, from diseases of the eyes to the bowels, and conditions rooted in chronic inflammation and immune dysfunction in particular.
Vitamin D deficiency is common around the world, even in sundrenched areas, yet many people, including physicians, are unaware they may be lacking this important nutrient.
Even the Indian Medical Association1 is pushing for a nationwide awareness campaign, noting that vitamin D deficiency is prevalent in India, making people more vulnerable to chronic diseases such as diabetes, heart attacks, stroke and cancer.
Despite its name, vitamin D is actually a steroid hormone, which you get primarily from either sun exposure or supplementation, along with some foods. Many of its health benefits are due to its ability to influence genetic expression.
Moreover, researchers have discovered that vitamin D is involved in the biochemical cellular machinery of ALL cells and tissues in your body. Hence, when you don't have enough, your entire body struggles to function optimally.
In this article I will review a number of the more recently appreciated health conditions in which vitamin D deficiency may play a significant role.
As a general rule, it would be wise to improve your vitamin D status regardless of what ails you, but if you suffer from any of the following conditions, optimizing your vitamin D is clearly indicated.
Remember that while sunlight is the ideal way to optimize your vitamin D, winter and work prevent more than 90 percent of those reading this article from achieving ideal levels without supplementation. The only one to know you have therapeutic levels of vitamin D is to measure it.
Dry Eye Syndromes and Macular Degeneration
According to a recent study published in the International Journal of Rheumatic Diseases,2,3 "patients with vitamin D deficiency should be evaluated for dry eye syndromes." You could easily turn that around and say that anyone with dry eye syndrome would be advised to optimize their vitamin D.
What these researchers found was that premenopausal women who were deficient in vitamin D had a greater risk of dry eye and impaired tear function. According to the authors:
"Dry eye and impaired tear function in patients with vitamin D deficiency may indicate a protective role of vitamin D in the development of dry eye, probably by enhancing tear film parameters and reducing ocular surface inflammation."
Vitamin D deficiency may also raise your risk of age-related macular degeneration (AMD) if you are genetically predisposed to it.
AMD is the No. 1 cause of blindness among American seniors, and in this study,4,5 the odds of manifesting the disease was greatest among women who had a combination of two risk alleles (genetic mutations) and the lowest vitamin D levels.
Overall, these women were nearly seven times more likely to develop AMD compared to women without the high risk genotype and who also had sufficient vitamin D.
According to the authors, their finding suggests "a synergistic effect between vitamin D status and complement cascade protein function." Lead author Amy Millen also noted:6
"Most people have heard that you should eat carrots to help your vision. However, there appear to be many other ways that adequate nutrition can support eye health. Having adequate vitamin D status may be one of them.
This is not a study that can, alone, prove a causal association, but it does suggest that if you're at high genetic risk for AMD, having a sufficient vitamin D status might help reduce your risk."
Link Between Vitamin D Deficiency and Multiple Sclerosis Strengthened
According to previous studies,22 you need a vitamin D level above 40 ng/ml to protect your baby from serious complications such as premature delivery and preeclampsia, and studies have confirmed there's a lifelong impact of vitamin D deficiency in pregnancy — ranging from childhood allergies to asthma, colds and flu, dental cavities, diabetes, and even strokes and cardiovascular disease23,24 in later life.
Two recent studies25,26 highlight the preventive power afforded by vitamin D during pregnancy against the development of childhood asthma. In the first, levels of vitamins D and E in the diets of pregnant mothers were assessed during early pregnancy, and then compared to health outcomes 10 years later.
Children born of mothers who had low levels of these two vitamins in their diet had an increased risk of developing asthma by the age of 10. As noted by Lung Disease News:27
"The long follow-up is important as it shows that the pregnant woman's diet is important throughout the life of her child."
The second study found that airway cells taken from newborns whose mothers had vitamin D and E deficient diets were more reactive against irritants and allergens, indicating a greater immune response. I firmly believe optimizing your vitamin D during pregnancy is one of the most important prenatal interventions you can implement for the health of your child. When a child is born deficient in vitamin D, his or her health can be significantly affected — in some cases for life.
The Protect Our Children NOW! campaign, discussed in the video above, has been launched to combat the problem of rising vitamin D deficiency among pregnant women, not only in the US, but around the world. The campaign will also raise global awareness about the general health risks associated with vitamin D deficiency. To learn more about this important campaign, including details on how to sign up, please following the hyperlink provided.
Vitamin D — A Simple, Inexpensive Way to Improve Your Health
An estimated 50 percent or more of the general population is at risk of vitamin D deficiency and insufficiency. Among school aged children, that percentage may be as high as 70 percent. As revealed above, this can raise your chances of any number of chronic or debilitating conditions.
Increasing levels of vitamin D3 among the general population could potentially prevent chronic diseases that claim nearly 1 million lives throughout the world each year. Incidence of several types of cancer could also be slashed in half. Vitamin D also effectively fights infections of all kinds, including the common cold and influenza, and perhaps even HIV.
Fortunately, the solution is both simple and inexpensive. Remember, to maximize the benefits of vitamin D, you need a vitamin D level of at least 40 to 60 ng/ml (a more ideal level may be 50 to 70 ng/ml), and all sources count — be it from sensible sun exposure, a tanning bed (restrict your use of tanning beds to those that use electronic ballasts), vitamin D-containing foods, and/or vitamin D supplements.
While sunlight is the ideal way to optimize your vitamin D, winter and work prevent more than 90 percent of those reading this article from achieving ideal levels without supplementation. The only one to know you have therapeutic levels of vitamin D is to measure it, and typical effective doses are between 5,000 to 10,000 units per day.