Meta-Analysis Finds No Causal Relation Between Vitamin D Status and Health — Physician’s First Watch

Medical News |
December 6, 2013

Meta-Analysis Finds No Causal Relation Between Vitamin D Status and Health

By Amy Orciari Herman

Vitamin D's frequently observed association with health conditions is not causal, according to a meta-analysis in the Lancet Diabetes & Endocrinology.

Researchers analyzed data from 290 prospective cohort studies and 172 randomized trials examining the relation between serum concentrations of 25-hydroxyvitamin D and nonskeletal health conditions. In the cohort studies, higher 25 (OH)D concentrations generally were associated with lower likelihood of cardiovascular disease, lipid disorders, glucose metabolism disorders, infectious diseases, multiple sclerosis, mood disorders, and total mortality. However, the randomized trials showed no effect of vitamin D supplementation on these outcomes.

The authors conclude that low serum vitamin D may simply be a marker of poor health. They speculate that low concentrations "could be the result of inflammatory processes involved in the occurrence and progression of disease."

Reader Comments (10)

Birge Physician, Family Medicine/General Practice

For optimal absorbtion, Vit D must be taken with oil (the Rx comes in an an oil/gel cap). The most effective efficient way is to take 1.25 mg (50,000 IU) once weekly. A "wash out" period (akin to overnight fasting for glucose) of 2 weeks followed by blood levels will guide you to the correct levels. There are precious few normal people who will take Vit D daily, once weekly is reasonable. One 86 year old patient took 50,000 daily for 3 months (her daughter started her on it) and after the 2 week washout period had a level of 71. She did not take it with oil, and with a "mature" GI tract did not absorb it as would a younger person. Taking D within 2 weeks of a blood test will result in very elevated levels, but these are spurious and of no clinical value. Rx 50,000 is essentially no different from OTC/health food store 50,000. For more background, check out Stross therapy. D is best taken with K2 (pills or diet) to prevent calcium deposition in arteries, kidneys et. al.

Mohamed Badawy Physician, Cardiology, saudi aramco

it is practical point of view as regards evidence based medicine

Bert Kummel Physician, Orthopedics

Problems with this study:
1. Lab determinations of 25OH vitamin D have wide margins of error.
2. How much vitamin D was prescribed and how was compliance measured?
3. Was PTH measured initially and later? Elevated PTH is probably a better measure of low 25 OH vitamnin D levels than the unreliable direct D measurements.

Jeff Rusteen M.DPN, AAS Other Healthcare Professional, Other

Since we now know what effect inflammation has on cancer, causing approximately 20% of CA, does taking a supplement during winter months have a positive effect, no effect or a harmful effect?

Charles Herron, MD Physician, Internal Medicine, Retired

Bad headline. Have to get down into the second paragraph to find the "nonskeletal" disclaimer.

Tch, tch, tch.

Wendy Bolt

The amounts of Vitamin D used in the studies were inadequate. Numerous studies have already shown the benefits of Vitamin D in disease prevention and cure, especially in several kinds of cancer. A "meta analysis" proves nothing. The researchers need to look further and look at the studies that actually got results. The recommended minimum amount of Vitamin D is 2000 IU per day. If a person is low, he or she will need to take many times that for a few months to "fill up the tank" so to speak. The body stores the vitamin and it takes a while to replenish the stores.The increasingly misnamed "RDA" is barely enought to prevent rickets, much less ensure optimum health. See for more information.

H Robert Silverstein Physician, Cardiology, Preventive Medicien Center

This is likely a case of "if you ask wrong question, you will get the wrong answer." Were they comparing, using adequate statistical force by virtue of large enough numbers of patients, what the effect was of a 25 OH D3 level in the 20s as compared to a 25 OH D3 level in the 50s (not 85 or above)? If the comparison was between levels in the 20s vs the 30's, then it is my bet that the essence of the report s written above would be correct--and of no value.

salem Physician, Surgery, General, jeddah

Good article

F.Ahmed MD Physician, Hematology, retired

If the Vit. D level is low, should one replace it along with other health measures to improve health or just he latter?

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