Vitamin D: The Versatile Nutrient

Saturday, January 30, 2010
Vitamin D: The Versatile Nutrient
 
Dr. Lynn Toohey, Ph.D, Nutrition
Colorado State University in Ft. Collins, CO

It has been over a decade now since my first newsletter on vitamin D, called
“Vitamin D: Discovering New Uses”. In that newsletter, I mentioned some of the
various conditions for which vitamin D was gaining recognition (beyond
increasing calcium/bone growth), including: Immune support (especially
autoimmune disorders and cancer research), cardiovascular disease, skin
disorders, nerve cell development (vitamin D is needed for NGF (nerve growth
factor), peripheral neuropathy, polycystic ovarian syndrome, etc. It seems that
newsletter title could easily be used again today, as vitamin D is still in the
news and still constantly being regarded as the vitamin that surprises us with
purported benefits, and discovered new uses.
After receiving some correspondence from a respected colleague (Dr. Deed
Harrison) on the connection of vitamin D and the brain/dementia, I decided to
write this article about vitamin D in the current news.

Vitamin D and the Brain
The observational evidence shows that low serum vitamin D levels are associated
with increased risk for cardiovascular diseases, diabetes mellitus, depression,
dental caries, osteoporosis, and periodontal disease, all of which are either
considered risk factors for dementia or have preceded incidence of dementia.
One developing hypothesis about how vitamin D affects brain development is
through bone morphogenetic proteins (BMP); vitamin D increases BMP, which
trigger stem cells to differentiate into many different types of cells,
including brain cells.1

In a study of 318 elderly participants, vitamin D insufficiency and deficiency
was associated with all-cause dementia, Alzheimer disease, stroke (with and
without dementia symptoms), and MRI indicators of cerebrovascular disease. The
researchers proposed that the findings suggest a potential vasculoprotective
role of vitamin D.2

Furthermore, a recent systematic review, while recognizing that the association
between serum vitamin D concentrations and cognitive performance needs to be
more clearly established, pointed out that three separate quality studies have
found four significant positive associations between serum vitamin D
concentrations and global cognitive functions.3

Vitamin D and Pregnancy
Scientific evidence suggests that that vitamin D deficiency may not only
contribute to the risk of developing a wide range of common chronic diseases,
but that the favorable biological effects of vitamin D that contribute to the
improvement of human health in humans may be even more critical during
pregnancy.

It appears that vitamin D insufficiency during pregnancy is potentially
associated with increased risk of preeclampsia, insulin resistance and
gestational diabetes mellitus. Furthermore, experimental data also anticipate
that vitamin D sufficiency is critical for fetal development, and especially for
fetal brain development and immunological functions. “Vitamin D deficiency
during pregnancy may, therefore, not only impair maternal skeletal preservation
and fetal skeletal formation but also be vital to the fetal "imprinting" that
may affect chronic disease susceptibility soon after birth as well as later”.4

Vitamin D and Mood
“Recent findings from a randomized trial suggest that high doses of supplemental
vitamin D may improve mild depressive symptoms”, and researchers are trying to
determine a) how vitamin D may affect monoamine function and
hypothalamic-pituitary-adrenal axis response to stress, b) whether vitamin D
supplementation can improve mood in individuals with moderate-to-severe
depression, and c) whether vitamin D sufficiency is protective against incident
depression and recurrence.5

Vitamin D and P. Neuropathy
“These results suggest that active vitamin D3 could treat peripheral neuropathy
by inducing NGF (nerve growth factor) production in the skin”.6
Besides nerve growth factor, vitamin D3 regulates the expression of several
other growth factors that influence important pathways in the body. These
factors include: insulin-like growth factor (IGF), neurotrophic factor,
hepatocyte (liver cell) growth factor, and vascular endothelial growth factor
(blood vessel wall lining). These growth factors are present in many areas of
the body that are vitamin D-sensitive organs.

Vitamin D and MS/Cancer
Vitamin D and MS/Cancer correlations and relationships are areas of my personal
research; these are topics for my next article, as they need an article
dedicated to these specific conditions. Thus next time, I will discuss some of
the articles I’ve written on MS7 and also the grant I’ve co-written with
Immunologist Dr. Don Bellgrau, concerning the nutritional influences of vitamin
D on dendritic cells and tumor antigen presentation.8
“Results from ecological, case-control and cohort studies have shown that
vitamin D reduces the risk of bone fracture, falls, autoimmune diseases, type 2
diabetes, CVD and cancer”.9

Vitamin D and lupus (SLE) and fibromyalgia:
Many patients with systemic lupus erythematosus (SLE) and fibromyalgia (FM) may
spend less time exposed to the sun than healthy individuals and thus might have
low vitamin D levels. When studied, half the SLE and FM patients had vitamin D
levels < 50 nmol/l, a level at which parathyroid (PTH) stimulation occurs. If
PTH stimulation occurs, calcium will be drawn from the bone, and risk for
osteoporosis will increase.

Additionally, hydroxychloroquine (HCQ) is a drug sometimes used in these
patients, and data from a study “suggest that in SLE patients HCQ might inhibit
the conversion to the active form of vitamin D10”.

SUMMARY & DOSAGES:
Vitamin D is both a hormone and a vitamin. Supplementation should be with the
active vitamin D3; 15 minutes of sun exposure 3 X week is adequate for most
people, although logistics and concerns about skin cancer make supplementation a
viable option. Recommended doses for vitamin D have been changing as the
benefits of supplementation have become evident; however, it is prudent to treat
this fat-soluble vitamin with respect.

Although when I received my PhD the upper limit was set at 2000-2400 IUs per
day, dosages these days sometimes run into thousands more IUs per day. The
caution would be that it is wise to monitor with lab tests (serum calcium or
vitamin D), especially for liability purposes, since the RDIs and upper limits
have not technically been changed yet. Blood calcium is tightly regulated, and
increases are a major concern. Vitamin D supplementation is contraindicated in
sarcoidosis, and although uncommon, can cause hypercalcemia.

References
1. Chen HL, Panchision DL. Stem Cells 2007; Vol. 25, no. 1: 63–68.
2. Buell JS, Dawson-Hughes B, et al. Neurology. 2009 Nov 25.
3. Annweiler C, Allali G, et al. Eur J Neurol. 2009 Oct;16(10):1083-9.
4. Lapillonne A. Med Hypotheses. 2010 Jan;74(1):71-5.
5. Bertone-Johnson ER. Nutr Rev. 2009 Aug;67(8):481-92.
6. Fukuoka M, et al. Skin Pharmacol Appl Skin Physiol 2001 Jul-Aug;14(4):226-33.
7. Toohey, L. J Brit Soc Allergy Env & Nutr Med 2005.
8. Bellgrau, D & Toohey, L. ACIR grant, 2009.
9. Wang S. Nutr Res Rev. 2009 Dec;22(2):188-203.
10. Huisman AM et al. J Rheumatol 2001 Nov;28(11):2535
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Labels: CBP Technique Chiropractic BioPhysics, Vitamin D