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. 83 February 1, 2013 Antioxidants: Miracle or Myth?

February 1, 2013

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“The hallowed notion that oxidative damage causes aging
and that vitamins might preserve our youth is now in doubt”
-M. W. Moyer, Scientific American February 2013

It was not just a humble roundworm that got us into this debate. it was a MUTANT roundworm, a worm commonly used for the study of aging.

Since the 1960’s the dominant theory of aging blamed a rising level of free radicals. Free radicals are highly reactive organic molecules produced in our bodies by oxidation. We all know that oxidation is “bad” because we learned in high school that it is oxidation that turns steel into rust. Free radicals cause “rust” in our body by mangling other cells, proteins, and even DNA. Therefore, an antioxidant that reduces free radicals will slow cell “mangling”, destruction, and aging. Having lots of antioxidants around should retard our aging process. “Drink red wine and take vitamin E.”  More than half of Americans believe in this theory and take considerable amounts of antioxidants like Vitamin E, Vitamin C,  and beta carotene (carrot juice). (JAMA 2007)

MIRACLE: “These high powered, super antioxidants fight dangerous free radicals, the source of oxidative stress and a leading cause of premature aging. CALL NOW to Receive Your FREE 30-Day Bonus Supply!” (Cape Cod Times ad January 20, 2013, E4)

This super antioxidant is an organic chemical called oligmeric proanthrocyanide, or OPC. It is found in grape seeds and certain pine bark. This particular brand of OPC’s touted by Dr. Fred Vaginini includes some other organic chemicals found in grape skins (hence the benefits of red wine) and other botanicals. It is called OPC Factor (TM);  $59.95 for a month’s supply ($35.99 on Amazon). The “landmark, double blinded research study by the prestigious National Institutes of Health” cited to support the ad’s claims was actually a small study by an NIH grantee in Philadelphia to measure changes in energy levels in 25 adult men who took OPC. The 2006 study  results were posted in 2008 as inconclusive.

In the 1990’s genetic science advanced to the point that worm and mice genes could be manipulated to block antioxidant production resulting in very high levels of free radicals. Much to the surprise of the scientists running the experiments those worms and mice with the highest levels of free radicals lived the LONGEST.

Exercise increases free radicals, but exercise is beneficial. A 2009 study of humans who exercised revealed that the ones that did NOT pop a lot of vitamins to lower their free radical levels  were physiologically healthier than those who did!   A 2010 study of mice bred to overproduce a specific “super” free radical actually lived 32% longer than the others. Free radicals rise as one ages, but it may be a result of aging and not the cause. I remember the classic graph showing the number of lung cancer deaths increasing as the number of refrigerators (or  indoor bathrooms) increased in the U.S. during the early phase of that debate.

MYTH: A 2007 systematic review of 68 clinical trials concluded that antioxidants do not reduce the risk of death. When the analysis is restricted to only the most vigorous, double-blinded studies certain antioxidants were linked to a 5% INCREASED risk of death. The American Heart Association and the American Diabetes Association now advise “that people should not take antioxidant supplements except to treat a diagnosed vitamin deficiency”.

“The literature is providing growing evidence that these supplements- in particular at high doses -do not necessarily have the beneficial effects that they have been thought to…We’ve become acutely aware of potential downsides.” -D. Albanes, Senior Investigator, National Cancer Institute

References:
“The Myth of Antioxidants”, Scientific American, Febuary 2013, 64-66, Melinda W. Moyer


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