Wednesday, November 05, 2008
Lack of Sunlight Leads to Infertility
An infertility study has revealed vitamin D deficiency among men who
are unable to impregnate their partners. The discovery surprised the
researchers, who were investigating the incidence of DNA fragmentation of
Fertility specialist Dr. Anne Clark screened the blood of almost 800
men with fertility problems, and found that almost a third had lower than
normal levels of vitamin D.
Sunlight is the major source of vitamin D.
a.. News.com.au October 19, 2008
Dr. Mercola's Comments:
The beneficial effects vitamin D can provide are nothing short
of amazing. So much so that optimizing your sun exposure, and hence the
levels of vitamin D in your body, may indeed be one of the most crucial
steps you can take in support of your long-term health.
I've discussed many of these benefits before (please see the
related article links below), but now it turns out vitamin D may also play
an important role in fertility.
Australian fertility specialist Dr Anne Clark found almost a
third of the 800 infertile men included in her study had lower than normal
levels of vitamin D, stating that:
" Vitamin D and folate deficiency are known to be associated
with infertility in women, but the outcomes of the screening among men in
our study group came as a complete surprise. Men in the study group who
agreed to make lifestyle changes and take dietary supplements had
surprisingly good fertility outcomes."
Previous studies, such as this one published in The Journal of
Nutrition, found that although vitamin D deficient female rats were capable
of reproduction, it reduced fertility by an astounding 75 percent,
diminished litter sizes by 30 percent, and impaired neonatal growth.
What Causes Vitamin D Deficiency?
As Dr Clark said, concerns about skin cancer is likely one major
contributing factor to the rampant vitamin D deficiency we now see around
the world, along with indoor work, and other lifestyle choices that do not
include direct sunlight exposure.
But evidence continues to mount in support of the obvious link
between healthy vitamin D levels and getting the right amount of sunshine,
which allows your body to produce it naturally. And unlike other medical
fads that boomed and bombed, this evidence is very strong and keeps growing.
Why Too Little Sun May Be Far Worse Than Too Much
In fact, the concept questions the longstanding conventional
belief that you should coat yourself with sunscreen whenever you're in the
Vitamin D bears the nickname the "sunshine vitamin" because your
skin produces it from ultraviolet ray exposure. Researchers now believe that
slapping on sunscreen actually contributes to far more cancer deaths than it
prevents, as doing so blocks this vital vitamin production.
Thus, while dermatologists and health agencies have long touted
that such lotions are needed to prevent skin cancer, many scientists are now
challenging that advice. Their main argument: Vitamin D is important for
preventing at least 16 different types of cancer, including:
a.. Breast cancer
b.. Prostate cancer
c.. Lung cancer
d.. Skin cancer
e.. Colon cancer
So, even if too much sun can lead to skin cancer, which is
rarely deadly, too little sun may be worse.
In fact, Dr. Edward Giovannucci, a Harvard professor, offered
such compelling evidence in one of his studies -- vitamin D may prevent 30
deaths for each death caused by skin cancer -- that the American Cancer
Society started reconsidering its own sun guidelines. Said Giovannucci in a
previous interview with the Associated Press:
"I would challenge anyone to find an area or nutrient or any
factor that has such consistent anti-cancer benefits as vitamin D. The data
is really quite remarkable."
The mechanisms by which vitamin D reduces your risk of cancer
are fairly well understood. They include:
a.. Enhancing calcium absorption (in the case of colorectal
b.. Inducing cell differentiation
c.. Increasing cancer cell apoptosis or death
d.. Reducing metastasis and proliferation
e.. Reducing angiogenesis
Fertility - What Does Vitamins Have to Do With It?
Now it seems we can add infertility to the list of health
ailments that are made worse by too little sun exposure. But other vitamins
and minerals can also be helpful in this area.
For example, did you know that vitamin C increases sperm quality
Vitamin C -- In one study, infertile men who were given 1,000
mg of vitamin C twice daily improved their sperm count, sperm motility, and
sperm morphology. The researchers stated vitamin C could be important as an
additional supplement to improve semen quality and increase chances of a
Vitamin E & Selenium -- Vitamin E and selenium can also
improve sperm motility. One study published in the Archives of Andrology
confirmed the protective and beneficial effects of vitamin E and selenium on
semen quality, and supported their use in male infertility treatment. Men
who are deficient in vitamin B12 can also suffer from poor motility (where
the sperm don't swim very well) so it is thought that taking this vitamin
may be helpful as well.
Zinc -- If low testosterone is the cause, zinc may help. In
one study, 37 infertile men were given 60mgs of zinc a day for six weeks. 22
of the men with low testosterone dramatically increased their sperm counts
and their testosterone, and 9 out of the 22 spouses became pregnant during
As usual, if you want to try the vitamin therapy approach, I
recommend you try to get most of your vitamins naturally, from the food you
eat, and in the case of vitamin D, from the sun (as it is not naturally
present in food).
Good sources of zinc include nuts and seeds. Vitamin C is
abundant in oranges, strawberries and sweet potatoes. Vitamin B12 is found
in butter, margarine, and eggs.
A whole food diet based on your nutritional type, and avoiding
processed foods, is the best way to ensure you're getting sufficient amounts
of essential vitamins and minerals.
You should also be aware that certain drugs can interfere with
your vitamin D absorption and metabolism, including cholestyramine
(Questran), Dilantin, and phenobarbital.
Additionally, because vitamin D is a fat-soluble vitamin, any
drug or substance that interferes with fat absorption may cause problems, as
may a low-fat diet.