and Vitamin D – A Comprehensive Guide to the Benefits of the
by Frank Murray, foreword by Ronald L. Hoffman, MD
Basic Health Publications Inc.
28812 Top of the World Drive, Laguna Beach, California 96251
Softcover; ©2008; $18.95; 234 pp.
The buzz is everywhere – a new
star has appeared on the horizon and is the talk of the town. Even
mainstream docs are urging their patients to take this supplement.
The recognition of vitamin D's many benefits has been a long time
coming. One reason – the usual lack of interest in nonpharmaceuticals;
and even now, some researchers believe D is a hormone rather than
a vitamin. Whichever it is, we now know that D is essential for
bone health, among other things; and the book cites many studies,
especially on postmenopausal women, reporting widespread deficiencies.
The more recent use of sunscreen has purportedly been to prevent
skin cancer; it was originally intended to prevent wrinkles or premature
aging of the skin from the sun. Since the ubiquitous use of sunscreen,
osteoporosis has become epidemic.
Low vitamin D status has now been linked to diseases such as breast
cancer, cardiovascular disease, multiple sclerosis, and diabetes.
However, the studies are so recent that outdated and misleading
dosages are still given in media reports to the public. In one study,
randomized trials using the currently recommended intakes of 400
IU/day of vitamin D showed no appreciable reduction in fracture
risk. By contrast, trials using 700–800 IU/day of the vitamin
found less fracture incidence, with and without supplemental calcium.
So dosage is crucial.
For people living in the southern latitudes, there's no lack of
vitamin D exposure. However, for those of us living in northern
climes, supplementation is essential – here in the Pacific
Northwest, I see more rain than sunshine most of the year.
Low vitamin D status seems to especially affect women and seniors.
Chapters on vitamin D and women's health, and vitamin D and seniors,
reflect the large amount of research accumulating on this essential
nutrient. Study after study shows the almost universal deficiency
in these populations. In one study, blood levels of 25-hydroxyvitamin
D concentrations and risk factors were evaluated in men and women,
ranging in age from 67 to 95, who were in the famous Framingham
Heart Study cohort. In the women, concentrations were inversely
associated with age and positively associated with supplemental
vitamin D intake and residence in Florida, California, and Arizona;
in men they were positively associated with serum creatinine concentrations.
The researchers noted that results from the population-based sample
of elderly people suggest that inadequate vitamin D status is an
important public health problem.
The chapter on cardiovascular disease reports that patients with
severe congestive heart failure had significantly lower vitamin
D metabolites and higher bone turnover. Another research team evaluated
the association between blood levels of 25-hydroxyvitamin D and
various cardiovascular disease risk factors. Their conclusion that
blood levels of vitamin D are associated with important cardiovascular
disease risk factors in American adults was published in Archives
of Internal Medicine in 2007.
There are additional chapters on amyotrophic lateral sclerosis,
cancer, celiac disease, cystic fibrosis, diabetes, and multiple
sclerosis – all with an abundance of studies showing the importance
of vitamin D status in many serious diseases and the widespread
deficiencies in Northern populations.
There's an important chapter on sunscreens and vitamin D, showing
that age-adjusted incidence and mortality rates from melanoma have
actually increased since sunscreens were introduced in the 1960s.
Aside from prolonged exposure to UV radiation, another potential
adverse effect of sunscreen is interference with the cutaneous synthesis
of vitamin D. Obviously, we still do not know enough about the sunscreens.
It would seem prudent to restrict our sun exposure to the short
time needed for vitamin D synthesis and no more, eliminating the
sunscreen. And don't forget the wide-brimmed hat.
Because vitamin D is potentially toxic, recommended intake has been
very low. Researchers now suggest that 5,000 IU/day is a safe and
adequate dosage for most people. Reinhold Vieth, PhD, of the University
of Toronto, reports: "Total body sun exposure easily provides
the equivalent of 10,000 IU/day of vitamin D, suggesting that this
is a physiologic limit."
Frank Murray is a well-known health writer, with many helpful books
for consumers; and Sunshine and
Vitamin D is no exception. Packed
with research studies, and exploring areas of controversy, this
book will help consumers evaluate their need for a vitamin D supplement,
which may turn out to be a very important health decision.