found that many other cells
and tissues of the body have the
biochemical machinery to synthesize and respond to vitamin
D. Thus, vitamin D may have
important effects on general
health and on many disease processes. For example, vitamin D
has effects on nerve, muscle, and
immune cells that could potentially affect the disease process
of MS.
done in relation to bone health.
There is general consensus, due
to well-conducted epidemiologic
and clinical trial studies, that
low vitamin D intake leads to
decreased bone density and that
vitamin D supplements may
improve bone density. In its
mild form, low bone density is
known as osteopenia and in its
severe form as osteoporosis.
provide therapeutic effects for
that condition.
Medical conditions
associated with
vitamin D deficiency
Presumably through
immune system
effects, vitamin D
deficiency has been
associated with
increased risk and
increased disease
severity of MS and
other immune diseases, including
diabetes and rheumatoid arthritis. Vitamin
D deficiency may also increase
the risk or severity of a long
list of other diseases, including
heart disease and multiple forms
of cancer. Inadequate vitamin
D has also been associated
with muscle weakness and an
increased risk of falls.
“Debatable”
Study quality
Risks of vitamin D
supplements
It has been known for decades
that very high doses of vitamin
D [ 50,000 IU or more daily]
may trigger high blood calcium
levels, impaired kidney function
and other serious side effects.
More recent studies
have raised the possibility—but have certainly not proven—
that long-term intake
of moderately high
doses of vitamin D,
could increase the risk
of death and the risk
of pancreatic, breast,
or prostate cancers,
heart disease, bone
fractures, and falls.
The recent IOM
report—which was
based on a review of a
wide range of studies
of vitamin D and calcium—
stated that the Tolerable Upper
Intake Level (UL) for adults,
which is the safe upper limit
for regular daily use, should be
4,000 IU for vitamin D and
2,000– 3,000 mg for calcium.
The report expressed concern
that adverse effects of vitamin
D could possibly be seen when
blood levels are higher than 50
ng/ml.
Are you confused yet?
Some sources of information,
such as the IOM report, caution
