Comments on: Vitamin D-bate D-bunked

By: mreades

mreades — Mon, 22 Feb 2010 14:02:55 +0000

The liquid is available in the US from several manufacturers.

By: jacqjolie

jacqjolie — Sat, 20 Feb 2010 19:07:55 +0000

Here’s a great youtube video with a seminar by Robert Heaney entitled “What’s a Vitamin D Deficiency?”

http://www.youtube.com/watch?v=emjCzaHtSrg

Here in Canada, we have vitamin D drops, but I haven’t seen them in the US. I supplement my kids milk with them in the fall, spring and winter.

By: George D. Henderson

George D. Henderson — Wed, 17 Feb 2010 09:16:11 +0000

I checked, and carotenoids do block UVA as well as UVB (in fact carotenoid sunscreens – the ubiquitous colourless carotene precursors phytoene and phytofluene – are being developed specifically to block UVA).
One thing about carotenoids is that, in plants, they are used to catch photon energy and conduct it across the chloroplast; they don’t just quench the solar energy, but pass it on quickly and safely to where it gets used in photosynthesis.
If this applied to humans, carotenoids might actually facilitate Vit d conversion – but that’s a very big if!
On the other hand, if lipid-soluble antioxidants are very slightly decreasing vit d conversion in those people who are already very vit d deficient, it might explain the lack of expected benefit in large epidemiological studies – especially those from high northern latitudes, or in hospitalised populations.

By: mreades

mreades — Wed, 17 Feb 2010 05:22:28 +0000

I’m surprised, too. Although it never really occurred to me, so maybe it hasn’t occurred to anyone else as well.

By: George D. Henderson

George D. Henderson — Mon, 15 Feb 2010 02:11:21 +0000

Dr Eades,

do you have any idea as to what effect UVB-blocking antioxidants such as carotenoids have on vitamin D intake from sunlight?
I understand that studies have shown no statistical increase in melanoma (as we might expect if they block tan but not UVA – if this is in fact the case), but I cannot find any linking antioxidants to vitamin D conversion.
I find I don’t burn or tan at all due to the antioxidants I take for Hep C. So I am careful to supplement some cod liver oil in summer, extra vit D in winter, regardless of sunlight exposure.
If antioxidants block vit D conversion even slightly this might be significant for those in high latitudes, on low-saturated fat diets. It might explain the CARET study results, for example.
I’m surprised that no-one seems to have studied it.

By: Anne

Anne — Fri, 05 Feb 2010 07:47:12 +0000

Hi Anna,
That was indeed probably me you remember posting about. I eat at least one portion of oily fish per day and sometimes two (I also have diabetes btw, atypical type 2, I�m thin and not insulin resistant). I wrote to Dr David Grimes, the doctor who Dr Davis had quoted in his blog, about fish and vitamin D. From what he replied to me it is still not clear that this is the reason my 25(OH)D is so high and Dr Grimes went on to advise me to accept injections of vitamin D2 from my endocrinologist ! This is not something I will do I hasten to add ! My endocrinologist�s rationale in wanting me to have D2 injections is that this is the only way he can be sure of the amount of supplemental D I am getting as he thinks the capsules I take are inaccurate. I take Carlson�s so I don�t think they are inaccurate as so many other people take them and don�t get these high levels of 25(OH)D !

By: Mary Titus

Mary Titus — Fri, 05 Feb 2010 01:16:02 +0000

Oh, I know testing is necessary. I will be testing soon but I would wager that my D levels have been quite low for most of my life. My mom had been fighting diabetes for 25 years which eventually lead to kidney failure. She developed pancreatitis and the antibiotic used to treat it caused her to get C-Diff which is comparable to mersa. She was able to survive the C-Diff but died 2 weeks later. Deep down, I will believe for the rest of my days that my mom passed away from vitamin D insufficiency.

By: Anna

Anna — Thu, 04 Feb 2010 23:48:56 +0000

Anne,

Am I correct in remembering you posted about your elevated 25 (OH)D result on another blog (Heart Scan blog?)? But i also seem to remember that you also regularly consume a high level of fatty fish compared to most people.

Fatty fish are one of the few Vit D rich food sources, and a high consumption rate could indeed make a significant difference in a 25 (OH)D test result.

By: mreades

mreades — Thu, 04 Feb 2010 19:39:04 +0000

You make an excellent point. The only real way to monitor how you are doing vitamin D-wise it to get tested regularly. Here is an excellent post on everything you need to know about vitamin D by Dr. William Davis of the Heart Scan Blog that lays it all out.

By: Anne

Anne — Thu, 04 Feb 2010 19:30:35 +0000

Just to put the other side of the story – I took 4,000 IU of D3 per day for four months and my 25(OH)D level reached 154 ng/ml (384 nmol/L). This was in the winter time so I wasn’t getting any sun at all. I live in the UK where we never get much sun anyway. After a complete break from D3 for several months I resumed at 2,000 IU per day and have been taking that for just over a year now – my last reading of 25(OH)D was 100 ng/ml (250 nmol/L). I have now cut down to 1500 IU D3 per day because there are some signs of abnormality – too high alkaline phosphatase levels associated with the 25(OH)D levels.

Everyone is different and some people need a lot of D3 and some people don’t. The only way to find out is to do lots of testing – I get tested every three months or so.