We have developed some pretty destructive health behaviors during the past few decades. We are consuming more and more processed foods, getting less and less exercise, and obesity rates are skyrocketing. Those are some of the most obvious (and visible) poor health decisions people are making; however, here’s one you may not have given much thought: the lack of exposure to direct sunlight.
We’re sure sunblock fanatics balked at that statement, but it’s true. Sensors in our skin cells absorb the UVB rays from the sun, and this helps our bodies produce vitamin D, which is one of the most crucial nutrients necessary for proper functioning. But with people spending more hours of their day indoors, and concerns about skin cancer prompting people to slather on thick layers of UVB-blocking lotions when they do go outside, vitamin D deficiency has become widespread… and it’s dangerous.
Vitamin D deficiency has been linked to numerous diseases, and much research has been done on the health benefits of vitamin D, especially during the past decade. A recent study published online ahead of print in the European Journal of Clinical Nutrition, reviewed the current research on solar ultraviolet-B (UVB) and vitamin D, and looked at global mortality rates.
In looking at data from six regions of the world — Africa, the Americas, Eastern Mediterranean, Europe, Southeast Asia and Western Pacific — the author noted, “The top six types of vitamin D-sensitive disease — cardiovascular disease (CVD), malignant neoplasms (cancer), respiratory infections, respiratory diseases, tuberculosis (TB) and diabetes mellitus — account for 59% of male deaths and 62% of female deaths globally. Another seven vitamin D-sensitive diseases [Alzheimer’s disease, falls, meningitis, Parkinson’s disease, maternal sepsis, maternal hypertension (pre-eclampsia) and multiple sclerosis] add 2 to 3% to the death rates related to vitamin D deficiency.”
The objective of the study was to estimate the reduction in mortality rates for the six geopolitical regions under the assumption that serum 25-hydroxyvitamin D (25(OH)D) levels increase from 54 to 110 nmol/l. Or, in laymen’s terms, the reduction in mortality rates that would be seen by doubling people’s vitamin D levels, as 25-hydroxyvitamin D is converted by our kidneys into an active form of the vitamin that our bodies use.
Overall, the author found a reduction in all-cause mortality rates ranging from 7.6 percent for African females to 17.3 percent for European females, with the reductions for males averaging 0.6 percent lower than for females. And the estimated increase in life expectancy was two years for all six regions. And for North America and Europe, estimates show doubling vitamin D levels could reduce the all-cause mortality rate by an estimated 15 percent to 20 percent and the direct economic burden of disease by an estimated 10 percent.
We’re going to go through the study, disease by disease, where the author found compelling evidence that doubling a person’s vitamin D level would have a significant impact, and highlight some of the research cited. (In interest of full disclosure, the author did cite as a conflict of interest that funding was received from the UV Foundation, the Sunlight Research Forum, Bio-Tech-Pharmacal, the Vitamin D Council and the Danish Sunbed Federation.)
Doubling vitamin D reduced the hazard ratio (HR) for cardiovascular disease by 18% in the six geopolitical regions.
Although findings have been somewhat mixed, vitamin D levels have been associated with reduced mortality rates for seven types of cancer: breast, colorectal, lung and prostate cancers; melanoma; non-Hodgkin’s lymphoma; and chronic lymphocytic leukemia.
For example, in one study conducted on postmenopausal women, the subjects were given 1,450 mg of calcium per day, 1,450 mg of calcium per day plus 1,100 IU per day of vitamin D or a placebo and then monitored for four years. (The serum 25(OH)D levels of those taking vitamin D increased from 72 to 96 nmol/l.)
Between the ends of the first and fourth years, those taking calcium had a 41% reduction in all-cancer incidence (not statistically significant), but the women taking calcium plus vitamin D had a 77% reduction (statistically significant).
According to the World Health Organization (WHO), respiratory infections kill more than 4 million people annually, with 98% of those deaths being attributed to lower respiratory infections. And seasonal influenza kills between 250,000 and 500,000 people each year.
It has been hypothesized, and two studies have supported the idea that epidemic influenza is largely seasonal because of the annual cycle of solar UVB and vitamin D production. And when it comes to pneumonia, a 2010 study of children in Kabul who took large doses of vitamin D3 showed a significantly reduced incidence rate.
Studies from Africa and the Western Pacific regions, where TB mortality rates are highest, generally report that those who develop TB have lower serum 25(OH)D levels. A 2010 study in Vietnam found that, “The prevalence of vitamin D insufficiency was 35.4% in men with TB and 19.5% in controls (P¼0.01). In women, there were no significant differences in serum 25(OH)D and serum (parathyroid hormone) levels between TB patients and controls.”
However, when it comes to treating TB, vitamin D does not seem be that beneficial, according to the research that has been conducted.
Type 2 Diabetes
Evidence is mounting that a combination of vitamin D and calcium can reduce the risk of diabetes. In a Harvard study, subjects who took 1,200 mg of calcium and 4,800 IU of vitamin D had a 33% lower risk of type 2 diabetes mellitus than those with an intake of 600 mg of calcium and 400 IU of vitamin D.
Falls and Fractures
The majority of deaths from falls and fractures are accidental falls in late age, and vitamin D deficiency is a risk factor due to musculoskeletal diseases.
Research has shown that vitamin D reduces the risk of multiple sclerosis (MS). As the author tells us, “The primary risk factor for MS is an adverse reaction to the Epstein–Barr virus. This reaction generally occurs in late winter or early spring, when serum 25(OH)D levels are lowest. As a result, MS prevalence increases with latitude.”
Get That Vitamin D!
We recommend that you go outside for at least 20-30 minutes each day, exposing multiple areas of skin to direct sunlight. In fact, that is the first recommendation in our free report 7 Steps to a Healthier and Happier You.
If it is not feasible for you to get 20-30 minutes a day of direct sunlight exposure, or if your doctor has advised you to avoid direct sunlight without applying sunblock, you should consider consuming foods that are fortified with vitamin D or taking a daily vitamin D dietary supplement.
Vitamin D is widely available in retail stores and online, and is inexpensive. You can get a monthly supply for $5-$10. Make sure to look at the supplement facts box on the bottle’s label to verify the product contains vitamin D3 in the form of cholecalciferol – the form of vitamin D best absorbed and utilized by the human body.
The National Academy of Sciences recommends 400-600 IU of vitamin D daily for healthy adults, but if you’re already vitamin D deficient, this amount is not adequate. We recommend adults consider dosage levels between 500 IU and 2,000 IU. (The National Academy of Sciences considers 2,000 IU the safe daily upper limit of vitamin D supplementation.)
If you are concerned that you may be vitamin D deficient, ask your doctor to order a vitamin D profile blood test. If you are deficient, your doctor can recommend a dosage level that is appropriate for your particular situation.
 Grant, WB. An estimate of the global reduction in mortality rates through doubling vitamin D levels. European Journal of Clinical Nutrition. 6 July 2011 [epub ahead of print]: 1-11.