Vol. 219 October 1, 2019 Vitamin D Supplement; Take It or Leave It?

October 1, 2019

Ever since the French sailors, weakened by scurvy, lost control of the seas to the British navy which was scurvy-free by vitamin C in the lime juice added to their daily ration of grog (hence the name “Limeys”), vitamins have been a subject of great interest and, even now, a lot of mystery. Everyone agrees that a little bit of them is essential for good health, but even two-time Nobel Prize winner Linus Pauling couldn’t convince all of us that a lot of vitamin C  could cure a cold. (1)

Vitamin D is currently the most popular vitamin to study because of some past research suggesting that vitamin D protects us from heart disease, particularly the elderly. A 2012 survey reported that about 20% of respondents were taking vitamin D supplements (multivitamin supplements were not included).  Supplemental vitamin D AND supplemental calcium have long been touted for preventing loss of bone density, or osteoporosis, especially in post-menopausal women. 

It is clear that Vitamin D deficiency can cause growth retardation and bone disease, particularly in the first years of life. It is a bit unclear as to how much of vitamin D we need. The American Academy of Pediatrics recommends vitamin D supplements of 400 units a day for breast-fed babies. Recommendations for minimum doses in other than infants range from 400 units to 2000 units a day. It is said to be almost impossible to be “vitamin deficient” on a normal diet nowadays, but certain very restricted vegan diets can cause some problems in rare cases.  Also, studies of Northern urban  children (less sun exposure) revealed “low” Vitamin D blood levels which stirred up a lot of discussion about its significance and about “what level was normal”. Too much of most vitamins can’t really hurt you too much. Most “excess” of vitamins ingested ( the amount over the minimum required to prevent a deficiency disease)  just ends up in the toilet via your urine.

A recent systematic review of a large number of peer-reviewed research studies on the use of supplemental Vitamin D to reduce the risk of cardiovascular disease was recently published. (2) This meta-analysis (our trade name for such huge reviews) of 21 randomized clinical trials with over 83,000 participants (mean age, 65) followed for 1 to 12 years showed that using a variety of Vitamin D supplements did NOT lower the risk for myocardial infarction, stroke, cardiovascular-related deaths, or all-cause deaths. This is “the best evidence to date that fails to support use of vitamin D supplementation for lowering cardiovascular risk.” (3)

Of course, the results of that meta analysis was muddied just a bit by another meta analysis of 52 clinical trials with over 75,000 participants (mean age, 74) with 1 year follow-up which showed that Vitamin D supplements was associated with 4 per 1000 persons fewer deaths from cancer in a small sub-group of participants. (4)  To further confuse the issue, it was noted that this small but significant difference occurred in only those people taking the D³ form of oral Vitamin D, not those taking the D² form. But, this review also revealed no cardiovascular benefits.

What about effects of vitamin D supplements on bone-density? If the recommended daily dose of vitamin D is from 400 to 2000 units, what if we took twice that? About 3% of U.S. adults take over 4000 units of vitamin D daily. A Canadian randomized study of 311 adults with pre-study normal vitamin D blood levels took either 400, 4000, or 10,000 units per day of supplemental vitamin D for three years.  Bone density actually DECREASED in those taking the higher doses. Also, the vitamin D blood levels in those taking the 400 units (recommended minimum) did not increase above normal. “The findings point to no benefit for bone integrity—and even harm—with high dose vitamin D supplementation in patients with adequate vitamin D blood levels.” (5) 

In today’s blog I offer evidence-based skepticism about the benefits of both vitamin C and vitamin D supplements. In my last blog I cautioned against vitamin E . . .at least the inhaled form. Is there a vitamin F supplement to continue my progression? Yes, there is! Vitamin F is an outdated term for omega-3 and omega-6 fatty acids,  but I think I’ll let that subject “sleep with the fishes” for the moment.

References
1. “Vitamin C and The Common Cold”, Linus Pauling, 1970 and 1976.
2. JAMA Cardiology 2019 Aug; 4:765
3. NEJM Journal Watch cardiology,vol.39, Oct. 2019)
4. NEJM 2019;380:33
5. JAMA 2019Aug27;322:736

 


Vol. 171 May 15, 2017 Medical Updates (Real News)

May 15, 2017

 

“The Only Thing That Is Constant Is Change -”― Heraclitus

 

 


Those TV ads work … for the drug companies.
A study of the effectiveness of TV ads (Direct-to-Consumer Advertising or DTCA) for prescribed testosterone supplements (no effectiveness in men without endocrine disease) in 75 regional markets from 2009 to 2013 showed that the addition of ONE TV ad per household per month for 4 years was associated with an increase in new blood tests of testosterone level, new prescriptions with blood level testing, and new prescriptions without any blood level testing. About 2% of the middle-aged men in this study of 17 million men received a testosterone prescription. (JAMA,Mar 21, 2017)

In other news, the British Medical Journal published a study of over 900,000 men which showed that those taking testosterone were 63% more likely to develop potentially fatal blood clots in the legs or lungs during the first six months of taking it. (BMJ, Nov. 13, 2016)

Vitamin D gets an “F”.
Vitamin D supplements became very much in vogue when some studies suggested that people with low blood levels had a higher risk of cardiovascular disease. BUT, in New Zealand 2500 adults were given 1000 units of vitamin D once a month and a matched group of 2500 were given placebo. The vitamin D blood level doubled in the supplemented adults, but at the end of 3 years both groups had identical rates of adverse cardiovascular events (12%). (JAMA Cardiol Apr 5, 2017)

PSA testing -“D” or “C”? It depends.
In 2012 the U.S. Preventative Services Task Force (USPSTF) gave the PSA blood test screening for prostate cancer a “D” – (not recommended) because of false positives leading to unnecessary procedures and treatment, and the fact that PSA screening prevented less than 1 prostate cancer-related death per 1000 men screened.

In 2017 the USPSTF is upgrading that “D” to a “C” (maybe a small benefit) but only for men aged 55-69. (Dare we call it a “gentlemen’s C” ?) The “D” remains for those over 70. This upgrade for the younger men is based mostly on the emergence of the “active surveillance” option to immediate surgery or radiation for positive PSA tests and biopsy. The USPSTF strongly recommends that physicians 1) explain all the risks and benefits of PSA testing to men from 55-69, 2) be aware of the patient’s “values and preferences”, and 3) practice effective “joint decision-making” with the patient. (J Watch General Medicine May 15, 2017)

In other news, a Michigan study of 431 men with localized prostate cancer discovered by PSA testing and confirmed by biopsy who opted for “active surveillance” rather than immediate surgery or radiation showed that only 31% actually followed the complete “active surveillance” protocol. (PSA testing every 6 months and annual repeat biopsy.) Another 31% complied with just the PSA test repeats, but not the biopsy. 22% did neither repeat PSA tests nor biopsy. Outcomes were not measured in this study, (J Urol Mar 2017)

Aspirin may get a third “A”
Aspirin is well-known to relieve pain, reduce inflammation, reduce fever, and reduce blood clotting. It does that by inhibiting the production of prostaglandins, a hormone-like substance in play in all those conditions. In 2000 scientists discovered that aspirin also increases our production of resolvins which also reduce our inflammatory response. We make resolvins from Omega-3 fatty acid precursors (hence the contemporary popularity of fish oil).

Investigators are very interested in a newly defined, third effect of aspirin which is unrelated to its role in anti-inflammation – aspirin’s interference in the ability of cancer cells to metastasize. Cancer cells apparently need to be coated with clumps of platelets in order to survive their trip through the blood stream to distal sites. In mice, aspirin’s anti-platelet action (the “reducing blood clots” function) has been found to interfere with platelet clumping around the cancer cell and successful migration of the cancer cells through blood vessels is inhibited. (Scientific American May 2017)

Trying to avoid sugary beverages? Don’t jump to diet soda.
A 10 year study monitoring 4000 people without diabetes for strokes and cognitive decline found that people who drank diet soda every day were three times more likely to develop strokes and dementia. In a separate study people who drank more juices and more sugar-sweetened soda than others were more likely to have poorer memory and smaller brains on MRI imaging than the other people. The researchers state clearly that this is not a cause and effect situation, just an “association”. (Stroke April 24, 2017)
“More research is needed.” Of course.
“Water is best.”

Bilingual brains remember their first language, even when they can’t speak it!
Korean-born adults who were adopted by Dutch families before the age of six and who did not speak nor understand Korean were better at distinguishing between the sound contrasts of the Korean language and could pronounce the Korean sounds much better than those Dutch adults who had no exposure to the Korean language as children. This better discrimination of sounds is not genetically based because numerous studies have shown that all infants are capable of reproducing all the sounds of all languages. “Remarkably, what we learn before we can even speak stays with us for decades.” (Duh!) (Royal Society Open Science, Mar 2017)

No federal money to study pistols or pot.
According to David Hemenway, Professor of Health Policy, Harvard School of Public Health, an average of 300 people get shot in the U.S. each day. One-third of them die. Twenty years ago the CDC funded about $2.6 million a year (“a small amount”) for firearms research. Now that funding is ZERO. Since 2006 Congress has pprohibited the CDC from gathering any gun-related statistics and developing a gun-related data base, but there is apparently no formal, official prohibition for funding gun-issue research,; just the CDC’s desire to “stay out of congressional crosshairs”.

NIH apparently has the same reticence. In the past 40 years over 486 NIH grants have been awarded in the areas of cholera, diphtheria, polio, and rabies which have caused 2000 deaths in the U.S. Over the same 40 years while 4 million people were shot in the U.S. , NIH has awarded 3 gun-issue research awards. (Note: this period of time is during the relatively scientific-friendly Clinton, Bush, and Obama administrations .)

Marijuana is still classified by the FDA and the DEA as a Schedule I substance which prevents any clinical trial or study of its medicinal benefits. Medicinal marijuana must have FDA required “drug development” studies to get off Schedule I, and those studies are virtually impossible while it is on Schedule I. (Note: current Attorney General Jeff Sessions said in April 2016: “Good people don’t smoke marijuana”) (Scientific American May 2017)


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