Low levels of vitamin D may raise a person's risk of premature death, a study by Johns Hopkins researchers shows.
The research followed other recent studies showing low levels of vitamin D are linked to certain cancers, diabetes, and bone and immune system problems, but this is the first research to connect vitamin D deficiency to a higher risk of death
Bioactive vitamin D or calcitriol is a steroid hormone that has long been known for its important role in regulating body levels of calcium and phosphorus, and in mineralization of bone. More recently, it has become clear that receptors for vitamin D are present in a wide variety of cells, and that this hormone has biologic effects which extend far beyond control of mineral metabolism.
The active form of vitamin D binds to intracellular receptors that then function as transcription factors to modulate gene expression. Like the receptors for other steroid hormones and thyroid hormones, the vitamin D receptor has hormone-binding and DNA-binding domains. The vitamin D receptor forms a complex with another intracellular receptor, the retinoid-X receptor, and that heterodimer is what binds to DNA. In most cases studied, the effect is to activate transcription, but situations are also known in which vitamin D suppresses transcription.
Each of the forms of vitamin D is hydrophobic, and is transported in blood bound to carrier proteins. The major carrier is called, appropriately, vitamin D-binding protein. The halflife of 25-hydroxycholecalciferol is several weeks, while that of 1,25-dihydroxycholecalciferol is only a few hours.
The vitamin D receptor binds several forms of cholecalciferol. Its affinity for 1,25-dihydroxycholecalciferol is roughly 1000 times that for 25-hydroxycholecalciferol, which explains their relative biological potencies
Scientists have long known that a lack of vitamin D can weaken our bones. A new study shows that low levels of this nutrient may also be linked to a higher chance of dying early from heart and circulation problems, as well as other causes.
ScienceDaily (Feb. 10, 2009) - Vitamin D is significantly associated with muscle power and force in adolescent girls, according to a new study. Although vitamin D is naturally produced in the body through exposure to direct sunlight, vitamin D deficiency has become widely common in the United States. Vitamin D deficiency has been shown to have a significant negative impact on muscle and bone health, and can lead to conditions including osteoporosis and rickets.
Diagnosis and treatment of vitamin D deficiency.
Cannell JJ, Hollis BW, Zasloff M, Heaney RP.
Expert Opin Pharmacother. 2008 Jan;9(1):107-18.
PMID: 18076342
The recent discovery - in a randomised, controlled trial - that daily ingestion of 1100 IU of colecalciferol (vitamin D) over a 4-year period dramatically reduced the incidence of non-skin cancers makes it difficult to overstate the potential medical, social and economic implications of treating vitamin D deficiency. Not only are such deficiencies common, probably the rule, vitamin D deficiency stands implicated in a host of diseases other than cancer. The metabolic product of vitamin D is a potent, pleiotropic, repair and maintenance, secosteroid hormone that targets > 200 human genes in a wide variety of tissues, meaning it has as many mechanisms of action as genes it targets. A common misconception is that government agencies designed present intake recommendations to prevent or treat vitamin D deficiency. They did not. Instead, they are guidelines to prevent particular metabolic bone diseases. Official recommendations were never designed and are not effective in preventing or treating vitamin D deficiency and in no way limit the freedom of the physician - or responsibility - to do so. At this time, assessing serum 25-hydroxy-vitamin D is the only way to make the diagnosis and to assure that treatment is adequate and safe. The authors believe that treatment should be sufficient to maintain levels found in humans living naturally in a sun-rich environment, that is, > 40 ng/ml, year around. Three treatment modalities exist: sunlight, artificial ultraviolet B radiation or supplementation. All treatment modalities have their potential risks and benefits. Benefits of all treatment modalities outweigh potential risks and greatly outweigh the risk of no treatment. As a prolonged 'vitamin D winter', centred on the winter solstice, occurs at many temperate latitudes, ≤ 5000 IU (125 μg) of vitamin D/d
"Women from India, Pakistan and Sri Lanka with insulin resistance showed marked improvement after taking vitamin D supplements, says a study.
Von Hurst, nutrition lecturer at the Institute of Food, Nutrition and Human Health at Albany, conducted the study for her doctoral thesis.
Insulin resistance is largely symptom-free and sufferers are unaware of their condition. 'Once it has fully developed into type-2 diabetes, it can be treated, but not cured,' says Von Hurst.
Von Hurst says that while diet and exercise play a major part in the onset of type-2 diabetes, her findings reinforce the importance of vitamin D from the sun and supplements to prevent type-2 diabetes. She also found evidence of vitamin D increasing bone strength in older women.
"
A prospective nested case-control study of vitamin D status and pancreatic cancer risk in male smokers.
Stolzenberg-Solomon RZ, Vieth R, Azad A, Pietinen P, Taylor PR, Virtamo J, Albanes D.
Cancer Res. 2006 Oct 15;66(20):10213-9.
PMID: 17047087
Higher vitamin D concentrations were associated with a 3-fold increased risk for pancreatic cancer (highest versus lowest quintile, >65.5 versus <32.0 nmol/L: OR, 2.92; 95% CI, 1.56-5.48, Ptrend = 0.001) that remained after excluding cases diagnosed early during follow-up. Contrary to expectations, subjects with higher prediagnostic vitamin D status had an increased pancreatic cancer risk compared with those with lower status. Our findings need to be replicated in other populations and caution is warranted in their interpretation and implication. Our results are intriguing and may provide clues that further the understanding of the etiology of this highly fatal cancer.
In conclusion, contrary to expectation, subjects with higher 25(OH)D concentrations were at greater risk for pancreatic cancer compared with those with lower concentrations in our prospective study with long-term follow-up. Caution is warranted in the interpretation and implication of our findings, however, as vitamin D inadequacy is an important public health problem and adequate status is desirable to prevent bone and other diseases (5). Our results, however, are intriguing and may provide clues that further the understanding of the etiology of this highly fatal cancer.
"Thursday, 17 December 2009
This blog is in response to Dr Briffa's post here. as I keep having problems commenting on his blogs.
While 44ng/ml is sufficient to not only maximize uptake of calcium (>32ng/ml) and ensure maximum bone mineral density (>42ng/ml), pregnant and nursing mothers should be aware that in order to maximize the amount of vitamin D3 in human breast milk 6400iu/daily was found to be necessary to raise (>58ng/ml) at latitude 32.
This is detailed in the Taylor, Wagner and Hollis paper.
Vitamin D supplementation during lactation to support infant and mother.
Although 4000iu/daily met the mothers daily needs in full it left babies being born with lower 25(OH)D status than required for optimum calcium absorption
They also found DAILY use of supplements was required by pregnant and nursing mothers to ensure an even daily Vitamin D3 supply to the foetus & baby.
It makes virtually no measurable difference for everyone else if you supplement daily or weekly.
While Dr Briffa will not be lactating he may be interested seeing in the
Grassrootshealth chart showing disease incidence by 25(OH)D status.
this may encourage him to go just another 10ng/ml higher and a bit nearer to the natural level at which human breast milk flows replete with D3."
Optimal serum 25-hydroxyvitamin D levels for multiple health outcomes.
Bischoff-Ferrari HA.
Adv Exp Med Biol. 2008;624:55-71. Review.
PMID: 18348447
DOI: 10.1007/978-0-387-77574-6_5
Recent evidence suggests that higher vitamin D intakes beyond current recommendations may be associated with better health outcomes. In this chapter, evidence is summarized from different studies that evaluate threshold levels for serum 25(OH)D levels in relation to bone mineral density (BMD), lower extremity function, dental health, risk of falls, admission to nursing home, fractures, cancer prevention and incident hypertension. For all endpoints, the most advantageous serum levels for 25(OH)D appeared to be at least 75 nmol/l (30 ng/ml) and for cancer prevention, desirable 25(OH)D levels are between 90-120 nmol/l (36-48 ng/ml). An intake of no less than 1000IU (25 meg) of vitamin D3 (cholecalciferol) per day for all adults may bring at least 50% of the population up to 75 nmol/l. Thus, higher doses of vitamin D are needed to bring most individuals into the desired range. While estimates suggest that 2000 IU vitamin D3 per day may successfully and safely achieve this goal, the implications of 2000 IU or higher doses for the total adult population need to be addressed in future studies.
"NEW YORK (Reuters Health) - Important news for seniors: A daily dose of vitamin D cuts your risk of falling substantially, researchers reported today.
But not just any dose will do. "It takes 700 to 1000 international units (IU) of vitamin D per day and nothing less will work," Dr. Heike A. Bischoff-Ferrari, who directs the Center on Aging and Mobility at the University of Zurich, Switzerland, noted in an email to Reuters Health.
Those recommendations - which are higher than those by the U.S. Institute of Medicine -- are based on the results of eight studies that looked at vitamin D supplements for fall prevention among more than 2,400 adults aged 65 and older. Falls were not notably reduced with daily doses of vitamin D lower than 700 IU.
An analysis of all eight studies, posted online today in the British Medical Journal, add weight to several others which have shown that vitamin D improves strength and balance, and bone health in the elderly, the researchers note."
"ScienceDaily (Oct. 8, 2009) - Women with breast cancer should be given high doses of vitamin D because a majority of them are likely to have low levels of vitamin D, which could contribute to decreased bone mass and greater risk of fractures, according to scientists at the University of Rochester Medical Center."
Scientists funded by the NCI analyzed vitamin D levels in each woman, and the average level was 27 nanograms per milliliter; more than two-thirds of the women had vitamin deficiency. Weekly supplementation with high doses of vitamin D -- 50,000 international units or more -- improved the levels, according to Peppone's study.
The U.S. Institute of Medicine suggests that blood levels nearing 32 nanograms per milliliter are adequate.
"Study finds inadequate levels of Vitamin D may significantly increase risk of stroke, heart disease and death
MURRAY, UT - While mothers have known that feeding their kids milk builds strong bones, a new study by researchers at the Heart Institute at Intermountain Medical Center in Salt Lake City suggests that Vitamin D contributes to a strong and healthy heart as well - and that inadequate levels of the vitamin may significantly increase a person's risk of stroke, heart disease, and death, even among people who've never had heart disease.
For more than a year, the Intermountain Medical Center research team followed 27,686 patients who were 50 years of age or older with no prior history of cardiovascular disease. The participants had their blood Vitamin D levels tested during routine clinical care. The patients were divided into three groups based on their Vitamin D levels - normal (over 30 nanograms per milliliter), low (15-30 ng/ml), or very low (less than 15 ng/ml). The patients were then followed to see if they developed some form of heart disease."
"DALLAS, Jan. 8 - The same vitamin D deficiency that can result in weak bones now has been associated with an increased risk of cardiovascular disease, Framingham Heart Study researchers report in Circulation: Journal of the American Heart Association.
"Vitamin D deficiency is associated with increased cardiovascular risk, above and beyond established cardiovascular risk factors," said Thomas J. Wang, M.D., assistant professor of medicine at Harvard Medical School in Boston, Mass. "The higher risk associated with vitamin D deficiency was particularly evident among individuals with high blood pressure."
In a study of 1,739 offspring from Framingham Heart Study participants (average age 59, all Caucasian), researchers found that those with blood levels of vitamin D below15 nanograms per milliliter (ng/mL) had twice the risk of a cardiovascular event such as a heart attack, heart failure or stroke in the next five years compared to those with higher levels of vitamin D."
Professor Departments of Nutritional Sciences, Laboratory Medicine, and Pathobiology, Bone and Mineral Laboratory, Pathology and Laboratory Medicine,
University of Toronto, Toronto, Canada M5S 3E2
Mount Sinai Hospital, 600 University Avenue, Toronto, Ontario, Canada
Effect of four monthly oral vitamin D3 (cholecalciferol) supplementation on fractures and mortality in men and women living in the community: randomised double blind controlled trial.
Trivedi DP, Doll R, Khaw KT.
BMJ. 2003 Mar 1;326(7387):469.
PMID: 12609940
CONCLUSION: Four monthly supplementation with 100 000 IU oral vitamin D may prevent fractures without adverse effects in men and women living in the general community.
Vitamin D3 and calcium to prevent hip fractures in the elderly women.
Chapuy MC, Arlot ME, Duboeuf F, Brun J, Crouzet B, Arnaud S, Delmas PD, Meunier PJ.
N Engl J Med. 1992 Dec 3;327(23):1637-42.
PMID: 1331788
CONCLUSIONS. Supplementation with vitamin D3 and calcium reduces the risk of hip fractures and other nonvertebral fractures among elderly women.
Fracture prevention with vitamin D supplementation: a meta-analysis of randomized controlled trials.
Bischoff-Ferrari HA, Willett WC, Wong JB, Giovannucci E, Dietrich T, Dawson-Hughes B.
JAMA. 2005 May 11;293(18):2257-64. Review.
PMID: 15886381
Conclusions Oral vitamin D supplementation between 700 to 800 IU/d appears to reduce the risk of hip and any nonvertebral fractures in ambulatory or institutionalized elderly persons. An oral vitamin D dose of 400 IU/d is not sufficient for fracture prevention.
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