Introduction:
A huge and growing amount of research has shown that vitamin D deficiency is very common, and with some studies showing at least 50% of the North American general population having low blood levels of vitamin D. This finding is thought to play a major role in the development in many of the chronic degenerative diseases. In fact, vitamin D deficiency may be the most common medical condition in the world, and vitamin D supplementation may be the most cost effective strategy in improving health, reducing disease, and living longer.
Those deficient in vitamin D have twice the rate of death and double the risk for many diseases, such as cancer, cardiovascular disease, diabetes, asthma and autoimmune diseases, such as multiple sclerosis.
Background Information:
Vitamin D3 is actually more of a “prohormone” than a vitamin. Humans can produce vitamin D3 by the reaction of a chemical in our skin in response to sunlight.
Some Risk Factors for Vitamin D Deficiency:
- Insufficient exposure to sunlight – working and playing indoors, covering up with clothes or sunscreen when outside, residing at a high latitude.
- Aging – seniors are at greater risk due to lack of mobility and skin that is less responsive to ultraviolet light.
- Darker skin – high incidence of vitamin D deficiency and its associated conditions in Blacks is widely documented. Blacks are at greatest risk of vitamin D deficiency due to higher skin melanin content.
- Obesity – fat-soluble vitamin D gets trapped in fat tissue, preventing its utilization by the body.
New Data:
A new study published in the British medical journal BMJ analyzed data on more than a million people to determine relationship between disease and blood levels of vitamin D. The data included evidence from double-blind trials — the gold standard in scientific research — that assessed whether taking vitamin D daily was beneficial.
Conducted by a team of scientists at Harvard, Oxford and other major universities this study provides further persuasive evidence that vitamin D3 protects against major diseases. Adults with lower levels of the vitamin in their systems had a 35% increased risk of death from heart disease, 14% greater likelihood of death from cancer, and a greater mortality risk overall. In analyzing the double-blind studies, middle-aged and older adults who took D3 had an 11% reduction in mortality from all causes, compared to adults who did not. The benefits were found only with D3, and they found no benefit in people taking the D2 form of the vitamin.
The researchers estimated that roughly 13% of all deaths in the United States could be attributed to low vitamin D levels.
Commentary:
The human genome contains more than 2,700 binding sites for active D3; these binding sites are located near genes that are involved in virtually every known major disease of humans.
If you want to know for certain if you are getting enough D3, get the blood test for 25-hydroxyvitamin D . The acceptable level is between 50 and 80 ng/ml because at levels below 50 ng/ml the body uses up vitamin D as fast as you can make it, or take it. Many doctors are now routinely checking vitamin D status in their patients.
To insure optimal vitamin D status without testing, recently most health experts, myself included, are advocating daily dosages of 2,000 to 5,000 IU, even in healthy adults. The research definitely supports this higher dosage level.
While vitamin D3 conceivably has the potential to cause toxicity, the reality is that dosages in the range of 2,000 to 5,000 IU per day are now recognized as being extremely safe levels. That dosage of 5,000 IU may seem like a huge amount, but keep in mind that the skin produces approximately 10,000 IU of vitamin D in response to 20–30 minutes of summer sun exposure. So, 5,000 IU is really a nominal amount of vitamin D. Just to put this amount into perspective, you would need to drink 50 glasses of milk in order to obtain 5,000 IU.
Reference:
Chowdhury R1, Kunutsor S, Vitezova A, et al. Vitamin D and risk of cause specific death: systematic review and meta-analysis of observational cohort and randomised intervention studies. BMJ. 2014 Apr 1;348:g1903.
