Experts Report Little Certainty in Vitamin D’s Potential Benefits « news@JAMA

Experts Report Little Certainty in Vitamin D’s Potential Benefits « news@JAMA

Conclusions in the statement include the following:

• Topical or oral vitamin D may help treat psoriasis, but more evidence is needed to determine its efficacy in treating other skin disorders or preventing skin cancer.
• No strong evidence exists to support the theory that vitamin D supplements reduce the risk of type 2 diabetes or the metabolic syndrome.
• Clinical trial evidence does not support taking vitamin D supplements to lower cardiovascular disease risk.
• Observational studies linking vitamin D with reduced cancer incidence are strongest for colorectal cancer but weak or inconsistent for breast, prostate, and all cancers combined.

The statement will be published in the June issue of the Endocrine Society’s Endocrine Reviews.

Vitamin D testing – articles of interest : The Lancet

Vitamin D testing (see sidebar)

Other Articles of Interest

Review Vitamin D and multiple sclerosis

Articles Common genetic determinants of vitamin D insufficiency: a genome-wide association study

Research Letters 25-hydroxyvitamin D-1α-hydroxylase in normal and malignant colon tissue

Articles High-dose vitamin D3 during intensive-phase antimicrobial treatment of pulmonary tuberculosis: a double-blind randomised controlled trial

Comment Genetic and environmental determinants of vitamin D status

Vitamin D testing – Authors' reply : The Lancet

Vitamin D testing – Authors' reply : The Lancet

Linked Articles

Correspondence Vitamin D testing :

Correspondence Vitamin D testing

Correspondence Vitamin D testing

Correspondence Vitamin D testing

Calcijex Injection (Calcitrol) Drug Information: Warnings and Precautions - (Calcitriol/Vitamin D/Hypercalcemia)

Calcijex Injection (Calcitrol) Drug Information: Warnings and Precautions - Prescribing Information at RxList

WARNINGS

Since calcitriol is the most potent metabolite of vitamin D available, prescription-based doses of vitamin D and its derivatives should be withheld or used with caution during treatment to avoid the risk of hypercalcemia.
A non-aluminum phosphate-binding compound should be used to control serum phosphorus levels in patients undergoing dialysis.
Overdosage of any form of vitamin D is dangerous (see also OVERDOSAGE).

abstract: Does vitamin D protect against DNA damage?

Does vitamin D protect against DNA damage?

Source: Mutation Research/Fundamental and Molecular Mechanisms of Mutagenesis

Vitamin D is a secosteroid best known for its role in maintaining bone and muscle health. Adequate levels of vitamin D may also be beneficial in maintaining DNA integrity. This role of vitamin D can be divided into a primary function that prevents damage from DNA and a secondary function that regulates the growth rate of cells. The potential for vitamin D to reduce oxidative damage to DNA in a human has been suggested by clinical trial where vitamin D supplementation reduced 8-hydroxy-2′-deoxyguanosine, a marker of oxidative damage, in colorectal epithelial crypt cells.

Studies in animal models and in different cell types have also shown marked reduction in oxidative stress damage and chromosomal aberrations, prevention of telomere shortening and inhibition of telomerase activity following treatment with vitamin D.

The secondary function of Vitamin D in preventing DNA damage includes regulation of the poly-ADP-ribose polymerase activity in the DNA damage response pathway involved in the detection of DNA lesions. It is also able to regulate the cell cycle to prevent the propagation of damaged DNA, and to regulate apoptosis to promote cell death. Vitamin D may contribute to prevention of human colorectal cancer, though there is little evidence to suggest that prevention of DNA damage mediates this effect, if real.

Very limited human data mean that the intake of vitamin D required to minimise DNA damage remains uncertain.

open access: What You and Your Patients Need to Know About Vitamin D

 Semin Cutan Med Surg 31:2-10 © 2012


Cancer

"Studies related to cancer and vitamin D have been some of the
most controversial and the most publicized. However, prospective
randomized controlled trials (RCTs) and observational studies conducted during many years fail to support vitamin D supplementation as a means to reduce cancer incidence or mortality overall or by cancer subtype.13.......Although the data do not support causation, if vitamin D
status is correlated with malignancy risk, it may be a proxy
for another effect of UV exposure that is independent of
vitamin D......"

Concluding Remarks

"Despite the extensive recent media coverage, the established
role of vitamin D in public health remains much the same as
100 years ago—a requirement for skeletal health, particularly
relevant to debilitated elderly populations. Most adults with
lighter skin easily maintain desirable 25(OH)D levels year round
by incidental protected sun exposure and a varied diet.
Seeking vitamin D through sun exposure is an imprecise
endeavor with well-documented risks of photo carcinogenesis
and photo aging. Thus, persons at high or intermediate
risk for skin cancer should practice “safe sun,” including
wearing sun-protective clothing, use of SPF sunscreen,
avoiding midday sun, and seeking shade. All persons should
avoid recreational sun beds. Routine monitoring of 25(OH)D
levels seems unwarranted; individuals concerned about possible
deficiency or “insufficiency” should be encouraged to
take a daily supplement of 400-1000 IU of vitamin D."

abstract: Long-Term Follow-Up for Mortality and Cancer in a Randomized Placebo-Controlled Trial of Vitamin D3 and/or Calcium (RECORD Trial)

Conclusions:
Daily vitamin D or calcium supplementation did not affect mortality, vascular disease, cancer mortality, or cancer incidence.

press release: Elsevier's Maturitas (European Menopause and Andropause Society (EMAS) ) publishes position statement on the role of vitamin D in postmenopausal women

Risks - When Too Much Vitamin D Is Too Much - NYTimes.com

references Johns Hopkins University study  published in The American Journal of Cardiology.

A Prospective Study of Serum 25-Hydroxyvitamin D (vitamin D) Levels, Blood Pressure, and Incident Hypertension in Postmenopausal Women

 authors.....for the Women’s Health Initiative Investigators

In postmenopausal women in this study, serum levels of 25(OH)D were not related to changes in blood pressure, and evidence for an association with lower risk of incident hypertension was weak.

Prognostic Role of Vitamin D Status and Efficacy of Vitamin D Supplementation in Cancer Patients: A Systematic Review - the Oncologist

Abstract  

Background. Whether or not hypovitaminosis D can influence the prognosis of cancer patients and whether or not vitamin D (vitD) supplementation improves outcome remain controversial.


Conclusion. Hypovitaminosis D seems to be associated with a worse prognosis in some cancers, but vitD supplementation failed to demonstrate a benefit in prostate cancer patients. The currently available evidence is insufficient to recommend vitD supplementation in cancer patients in clinical practice.

Note: per reference, one study included -  ovarian cancer

(Tamez S, Norizoe C, Ochiai K et al. Vitamin D receptor polymorphisms and prognosis of patients with epithelial ovarian cancer. Br J Cancer 2009; 101:1957–1960.)

Vitamin D Supplementation: An Update: Medscape

Note: Medscape requires registration (free)

The Power Of D (Vitamin D) - Science News

My Healthy Today - Menopause Increasing daily calcium will not reduce the risk of fractures in later life

The authors conclude that while low levels of calcium intake (less than 700 mg per day) increase the risk of fractures and osteoporosis, there is no need to start increasing calcium intake above the amount. Increases did not further reduce the fracture and osteoporosis risk.

EvidenceUpdates + professional commentaries (numerous): Calcium supplements with or without vitamin D and risk of cardiovascular events: reanalysis of the Women`s Health Initiative limited access dataset and meta-analysis

OBJECTIVES: To investigate the effects of personal calcium supplement use on cardiovascular risk in the Women`s Health Initiative Calcium/Vitamin D Supplementation Study (WHI CaD Study), using the WHI dataset, and to update the recent meta-analysis of calcium supplements and cardiovascular risk.

DESIGN: Reanalysis of WHI CaD Study limited access dataset and incorporation in meta-analysis with eight other studies.........

Conclusions: Calcium supplements with or without vitamin D modestly increase the risk of cardiovascular events, especially myocardial infarction, a finding obscured in the WHI CaD Study by the widespread use of personal calcium supplements. A reassessment of the role of calcium supplements in osteoporosis management is warranted.

free full access: Calcium supplements with/without vitamin D and risk of cardiovascular events: reanalysis of the Women’s Health Initiative - bmj.com (including responses)

Abstract/Conclusions:
Calcium supplements with or without vitamin D modestly increase the risk of cardiovascular events, especially myocardial infarction, a finding obscured in the WHI CaD Study by the widespread use of personal calcium supplements. A reassessment of the role of calcium supplements in osteoporosis management is warranted.

excerpt (from full text):

"...An important question that arises is whether co-administered calcium and vitamin D affects cardiovascular risk. The Women’s Health Initiative reported no adverse effect of calcium and vitamin D (1 g calcium/400 IU vitamin D daily) on any cardiovascular end point in their large (n=36 282), seven year, randomised, placebo controlled trial.3 4 However, 54% of the participants were taking personal (non-protocol) calcium supplements at randomisation and 47% were taking personal vitamin D supplements, effectively rendering this trial a comparison of higher dose and lower dose calcium and vitamin D for most of the participants.

Allowing clinical trial participants free access to the intervention being studied is unusual and has the potential to obscure both adverse and beneficial effects..."

Vitamin D and Prevention of Cancer — Ready for Prime Time? — NEJM

"Despite biologic plausibility and widespread enthusiasm, the IOM committee found that the evidence that vitamin D reduces cancer incidence and related mortality was inconsistent and inconclusive as to causality.
New trials assessing moderate-to-high-dose vitamin D supplementation for cancer prevention are in progress and should provide additional information within 5 to 6 years.
Although future research may demonstrate clear benefits of vitamin D related to cancer and other nonskeletal health outcomes, and possibly support higher intake requirements, the existing evidence falls short."

full free access: Meta-analysis: Circulating vitamin D and ovarian cancer risk

OBJECTIVE: To review and summarize evidence from longitudinal studies on the association between circulating 25 hydroxyvitamin D (25(OH)D) and the risk of ovarian cancer (OC).


RESULTS: Overall, ten individual-level studies were included that reported on the association between circulating vitamin D levels and OC incidence..........

CONCLUSIONS: A tentative inverse association of circulating 25(OH)D with OC incidence was found, which did not reach statistical significance but which requires clarification by additional studies due to potentially high clinical and public health impact.

Research Highlights

►As we know, this is the first systematic review and meta-analysis evaluating the association between serum 25(OH)D levels and ovarian cancer risk.
►The method for comprehensive trend estimation from summarized dose–response data was used for combining all results from individual studies so far.
►A potential weak inverse association between serum vitamin D and ovarian cancer risk was found in this meta-analysis.

Determinants of geographic patterns of diseases: interaction of lactose/lactase status and sunshine exposure - Jnl Med Hypotheses

".........The patterns related to sunshine (Vitamin D) reflect that obtained with national lactase status proportions and also corroborate a literature review. However, correlations are weak to moderate and only ovarian cancer reached conventional statistical significance. Because these comparisons are based on modest number of national data firm conclusions cannot be made....."

(full access) Review: Vitamin D in combination cancer treatment - Journal of Cancer