25-hydroxyvitamin D levels and the risk of mortality in the general population.
Melamed ML, Michos ED, Post W, Astor B.
Arch Intern Med. 2008 Aug 11;168(15):1629-37.
PMID: 18695076
Back to the future: a new look at 'old' vitamin D.
Chun RF, Adams JS, Hewison M.
J Endocrinol. 2008 Aug;198(2):261-9. Epub 2008 May 21.
PMID: 18495944
DOI: 10.1677/JOE-08-0170
Cutting edge: vitamin D-mediated human antimicrobial activity against Mycobacterium tuberculosis is dependent on the induction of cathelicidin.\nLiu PT, Stenger S, Tang DH, Modlin RL.\nJ Immunol. 2007 Aug 15;179(4):2060-3.\nPMID: 1767546
Vitamin K in the treatment and prevention of osteoporosis and arterial calcification.\nAdams J, Pepping J.\nAm J Health Syst Pharm. 2005 Aug 1;62(15):1574-81. Review.\nPMID: 16030366
Vitamin D protects bone, preserves muscle strength, and regulates cell growth and energy metabolism. It also offers some protection against cancer and other disease, but are these effects really important for health and life expectancy? The answer seems to be a resounding yes.
The vitamin K dependant protein osteocalcin may have a positive effect on reducing obesity and diabetes, suggests a new study with mice.\nResearchers writing in the journal Cells studied the effect bone cells have in energy regulation, and found that osteocalcin plays a key role in regulating insulin activity.
Th1/Th2 balance: the hypothesis, its limitations, and implications for health and disease.
Kidd P.
Altern Med Rev. 2003 Aug;8(3):223-46. Review.
PMID: 12946237
Th1 pathways typically produce activation of cytotoxic T
lymphocytes (Tc), NK cells, macrophages, and monocytes, all of
which can attack cancer cells and generally defend against tumors.
55 IFN-gamma and other Th1 cytokines are typically lower in
advanced cancer patients, while the Th2 marker IL-4 can be higher
or unchanged.56 Nodules of non-small cell lung cancer freshly
removed from patients expressed a marked imbalance toward Th2, as
did biopsy samples from basal cell carcinoma.57 In prostate cancer
patients IL-2 was low (Th1) and IL-10 high.58 IL-10 is a confirmed
Th1-suppressive cytokine, and heightened IL-10 is a common factor
in cancer.55
IL-10 has a variety of suppressive effects that include inhibiting
Th1 cytokine production, down-regulating APC and NK cell function,
and lowering overall T-cell proliferation.57 Especially under the
influence of IL-4 (Th2), tumor cells apparently up-regulate IL-10
that suppresses nearby killer cells. Tumor-derived IL-10 has been
documented in lymphoma, ovarian carcinoma, melanoma, neuroblastoma,
and renal cell and colon carcinoma.57 IL-12 is another cytokine
that can be up-regulated by Th1 activity and inhibited by Th2.59 A
low IL-12/IL-10 ratio was found in cervical cancer patients.55
Recent clinical studies suggest elevated IL-10 is predictive of a
poor prognosis. 57 With both IL-4 and IL-10 being proven inhibitors
of Th1 and promoters of Th2 activity, the recognized capability of
cancerous tissue to suppress immunity is readily rationalized.
Th1/Th2 balance: the hypothesis, its limitations, and implications for health and disease.
Kidd P.
Altern Med Rev. 2003 Aug;8(3):223-46. Review.
PMID: 12946237
Melanoma growth is reduced in fat-1 transgenic mice: impact of omega-6/omega-3 essential fatty acids.
Xia S, Lu Y, Wang J, He C, Hong S, Serhan CN, Kang JX.
Proc Natl Acad Sci U S A. 2006 Aug 15;103(33):12499-504. Epub 2006 Aug 3.
PMID: 16888035
doi: 10.1073/pnas.0605394103
In vitro experiments showed that addition of the n-3 fatty acid eicosapentaenoic acid or PGE(3) inhibited the growth of B16 cell line and increased the expression of PTEN, which could be partially attenuated by inhibition of PGE(3) production, suggesting that PGE(3) may act as an antitumor mediator. These data demonstrate an anticancer (antimelanoma) effect of n-3 fatty acids through, at least in part, activation of PTEN pathway mediated by PGE(3).
25-hydroxyvitamin D levels inversely associate with risk for developing coronary artery calcification.
de Boer IH, Kestenbaum B, Shoben AB, Michos ED, Sarnak MJ, Siscovick DS.
J Am Soc Nephrol. 2009 Aug;20(8):1805-12. Epub 2009 May 14.
PMID: 19443637
doi: 10.1681/ASN.2008111157
"In conclusion, lower 25-hydroxyvitamin D concentrations associate with increased risk for incident CAC. Accelerated development of atherosclerosis may underlie, in part, the increased cardiovascular risk associated with vitamin D deficiency."
25-Hydroxyvitamin D and functional outcomes in adolescents.
Lamberg-Allardt CJ, Viljakainen HT.
Am J Clin Nutr. 2008 Aug;88(2):534S-536S. Review.
PMID: 18689396
CONCLUSIONS
Cross-sectional studies have shown a relation among serum 25(OH)D concentration, serum PTH concentration, and BMD in adolescents. Long-term randomized controlled intervention studies have shown that vitamin D3 supplementation has a positive effect on BMD in adolescence; some of these studies found an effect with doses as small as 5 µg (200 IU) to 10 µg (400 IU) per day, or without supplemental calcium.
Why would vitamin D be prescribed when vitamin D3 is available over-the-counter?
Let's review the known differences between vitamin D2 (ergocalciferol) and vitamin D3 (cholecalciferol):
--D3 is the human form; D2 is the non-human form found in plants.
--Dose for dose, D3 is more effective at raising blood levels of 25-hydroxy vitamin D than D2. It requires roughly twice to 250% of the dose of D2 to match that of D3 (Trang H et al 1998).
--D2 blood levels don't yield long-term sustained levels of 25-hydroxy vitamin D as does D3. When examined as a 28-day area under the curve (AUC--a superior measure of biologic exposure), D3 yields better than a 300% increased potency compared to D2. This means that it requires around 50,000 units D2 to match the effects of 15,000 units D3 (Armas LA et al 2004).
--D2 has lower binding affinity for vitamin D-binding protein, compared to D3
--Mitochondrial vitamin D 25-hydroxylase converts D3 to the 25-hydroxylated form five times more rapidly than D2.
--As we age, the ability to metabolize D2 is dramatically reduced, while D3 is not subject to this phenomenon
ScienceDaily (Aug. 27, 2009) - Researchers have established the conditions that foster formation of potentially dangerous levels of a toxic substance in the high-fructose corn syrup (HFCS) that is often fed to honey bees. Their study, which appears in the current issue of ACS' bi-weekly Journal of Agricultural and Food Chemistry, may also have implications for soft drinks and dozens of other human foods that contain HFCS. The substance, hydroxymethylfurfural (HMF), forms mainly from heating fructose.
A new study has concluded that one key part of the immune system, the ability of vitamin D to regulate anti-bactericidal proteins, is so important that is has been conserved through almost 60 million years of evolution and is shared only by primates, including humans - but no other known animal species.
White Europeans could have evolved as recently as 5,500 years ago, according to research which suggests that the early humans who populated Britain and Scandinavia had dark skins for millenniums.
It was only when early humans gave up hunter-gathering and switched to farming about 5,500 years ago that white skin began to be favoured, say the researchers.
This is because farmed food was deficient in vitamin D, a vital nutrient. Humans can make this in their skin when exposed to sunlight, but dark skin is much less efficient at it.