Insufficient vitamin D is linked to virtually
EVERY age-
related disorder including cancer , vascular
disease, and chronic inflammation.
Just to
give you an example regarding the importance
of this hormone and the role it plays in a healthy
immune system, I will discuss its role in preventing
upper respiratory infections and the
flu.
Adults and children with higher vitamin D levels
contract substantially fewer cold, flu, and other viral
infections.
Specific biological mechanisms have been identified
to explain how vitamin D protects against so many
human ailments.
Vitamin D from all sources (sunlight, sun
lamps, or
supplements) reduces the incidence of respiratory
infections.
Dutch children with the least sun
exposure are twice as likely to develop a cough and
three times more likely to develop a runny nose
compared with children with the most sun
exposure.
When Russian athletes were given sun lamps to
stimulate vitamin D synthesis in the body, there were
50% fewer respiratory infections and far fewer days of
absence.
Children with the lowest vitamin D serum levels are 11
times more likely to develop respiratory infection.
When a high dose of vitamin D was
administered (for six weeks) to children with frequent
respiratory infections, the result was a complete
disappearance of such infections in the following six
months.
In a controlled trial of African women, a low dose (800
IU a day) of vitamin D resulted in a three-fold reduction
in cold and flu symptoms compared to those given
placebo.
Influenza kills around 36,000 Americans each year.
Ensuring optimal vitamin D status could reduce
influenza incidence and mortality.
Antimicrobial peptides are components of the immune
system that protect against bacterial, fungal, and viral
infections. Secreted by immune cells throughout the
body, antimicrobial peptides damage the outer lipid
membrane of infectious agents (including influenza
viruses), rendering them vulnerable to
eradication.
Recent studies confirm that vitamin D dramatically
upregulates the expression of these antimicrobial
peptides in immune cells.
There is now a
definitive
biological mechanism to explain why vitamin D
confers such dramatic protection against common
winter illnesses.
What Are Minimum Vitamin D Blood Levels?
When blood is tested to assess vitamin D status, what
is actually measured is the metabolically active 25-
hydroxyvitamin D form of the vitamin in the
serum.
When irrefutable data emerged about vitamin D's role
in preventing disease, experts initially recommended
a minimum target blood level of 30 ng/mL of 25-
hydroxyvitamin D.
In recognition of findings showing reduced incidences
of disease in those with higher vitamin D levels, the
standard laboratory reference range for 25-
hydroxyvitamin D was raised to 32-100
ng/mL.
Based on recent and conclusive published studies,
the new minimum target level for
optimal disease prevention is believed to be over 50
ng/mL of 25-
hydroxy-vitamin D.
John Cannell, MD, the president of The Vitamin D
Council, a non-profit group advocates higher
vitamin D intake.
According to a letter written
by
Dr. Cannell, adults need to take 5,000 IU a day of
vitamin D to put the vast majority of them (97.5%)
above the 50 ng/mL level.
To answer the
question as
to exactly how much vitamin D3 an individual needs
requires a blood test. This is a hormone after all. It
should be reevaluated just like any other hormone
level would be.
Those with a rare disorder called sarcoidosis, severe
renal impairment, primary hyperparathyroidism, or any
condition resulting in an elevated calcium level in the
blood should consult with their physician before taking
vitamin D supplements.
