Vitamin D Recommendations for Blacks
I have lowered my vitamin D recommendations for black people black people with type 2 diabetes based on some recent, albeit preliminary, research.
Here is the paragraph I added to the article Bones, Vitamin D, and Calcium:
A 2010 study on obese African-Americans with type 2 diabetes showed that those with higher blood levels of vitamin D had more calcification of some arteries (but not others) (35). In a related article, Vitamin D levels have different effects on atherosclerosis in blacks and whites, the lead researcher, Barry I. Freedman, MD, stated, “We should use caution when supplementing vitamin D in black patients while we investigate if we are actually worsening calcium deposition in the arteries with treatment.” That said, there has also been concern about black people not getting enough vitamin D (36). It seems prudent, then, for black people to get moderate amounts of sun and if they cannot, to supplement with smaller amounts of vitamin D, such as 250 IU per day. It seems prudent, then, for black people who have type 2 diabetes not to overdo vitamin D supplementation and take closer to the DRI until more research is conducted.
References
35. Freedman BI, Wagenknecht LE, Hairston KG, Bowden DW, Carr JJ, Hightower RC, Gordon EJ, Xu J, Langefeld CD, Divers J. Vitamin d, adiposity, and calcified atherosclerotic plaque in african-americans. J Clin Endocrinol Metab. 2010 Mar;95(3):1076-83. Epub 2010 Jan 8. (Abstract)
36. Harris SS. Vitamin D and African Americans. J Nutr. 2006 Apr;136(4):1126-9. PubMed Abstract..
March 20th, 2010 at 7:00 pm
Do you think that the use of obese diabetes patients for this study is meaningful? In other words, is either the obesity or diabetes more of an issue than the ethnicity of the patient?
March 20th, 2010 at 7:51 pm
Vegan Fit,
I would imagine that people who are not obese and do not have type two diabetes would have much less calcification of the arteries than the people in this study, and possibly so much less that vitamin D would not affect it. It’s not the best piece of evidence for making recommendations to the general public and I have to admit that I have not researched this subject further than what I referenced in the post and in the article on vitamin D I linked to. I don’t like changing recommendations on every piece of new evidence that comes out but in this case it seemed prudent to me.
I just found this abstract which indicates higher vitamin D would not cause cardiovascular disease in black people, and might even help prevent it. The reason I was so quick to change my recommendations is that they are much higher than the current RDA. Many vitamin D researchers think the RDA is much too low, but this is controversial.
So, in summary, I thought it was prudent to adjust my vitamin D recommendations to closer to the RDA until more is known.
March 22nd, 2010 at 12:57 pm
It will be interesting to see how the vitamin D research develops over the next few years. In the meantime, I think all adults should get their levels tested to determine whether supplementation should be considered.
March 22nd, 2010 at 1:00 pm
Vegan Fit,
It can’t hurt. Someone like me, who makes sure I get plenty of mid-day sun, should be safe.
March 23rd, 2010 at 10:29 am
Hello Jack, always a pleasure to gather information from you.
I’m a bit concerned though because of you lowering the recommendations for Blacks based on just one finding, especially when considering that your information is geared towards vegans, of who very few suffer from diabetes II and obesity.
Both me and my husband (who is black) happen do be tall and overweight, but not obese vegans from Germany and we have been trying to get our 25(OH)D levels above 100 nmol/l 40ng/ml. The dose which eventually was required to achieve this was 10,000 IU Ergocalciferol per day, yes, that’s 10 thousand. We started out with 1600 which didn’t get us above 50nmol/l 20ng/ml. Even at 10,000 IU, it took several months. Our serum calcium has always been normal, hovering around 2.30 mmol/l.
Germany simply doesn’t have the type of weather for any meaningful synthesis going on, as the result of the Max-Rubner-Study showed, if taking the “new good value” for Vitamin D of 30ng/ml, 90% of the Germany population is clinically deficient.
I’m faintly remembering that Vitamin-D-*deficiency*-related thyroid conditions, like secondary hyperparathyroidism, can make some people oversensitive to Vitamin D, in which case perhaps *not enough* Vitamin D was present in these cases to get rid of the sHPT! I’m just wildly speculating of course. but oversensitivity can result in the same symptoms as intoxication. So it could well be, that, counter-intuitively, raising the intake of Vitamin D with perhaps a large single dose to achieve a good 25(OH)D value, would have eradicated the sHPT and thus also decreased the oversensitivity.
And the way Diabetes affects the kidney in particular, I just think it’s much to early to lower recommendations, especially for a group who is particularly affected by Vitamin D deficiency. I have my doubts that nonvegan patients with impaired kidney function, can serve as a base of recommendation for your typically slim black vegan (waves to black vegans out there).
Greetings from Berlin
March 24th, 2010 at 10:46 am
Ava,
I have reconsidered and changed my recommendations for black people to be the same as for other people, 1,000 IU, unless they have type 2 diabetes in which case I recommend the US DRI. Thank you for your message!
Jack
March 27th, 2010 at 5:52 am
It seems (not too much to my surprise), that this has all been a terrible mistake:
http://www.vitamindcouncil.org/newsletter/vitamin-d-race-and-cardiovascular-disease.shtml
March 29th, 2010 at 3:26 pm
Ava,
I can’t find citations for the article on the Vitamin D Council’s page. I found a citation in what appears to be a reprint of the article:
http://www.foodconsumer.org/newsite/Nutrition/Vitamins/vitamin_d_and_heart_disease_2503100419.html
But the paper cited does not mention looking at black people as a subgroup. I searched for other papers by the author and didn’t find any that appeared to mention this.
I’m not saying that I doubt what the Vitamin D Council article is saying, but it would be nice to see it confirmed somewhere. I will try writing the author to see if he can provide a citation for the information.
May 20th, 2010 at 9:29 pm
As of May 20, 2010, Dr. Cannell of the Vitamin D Council has not responded to my request for a citation for his claim that “And, in direct contradiction to the Wake forest study, Dr. de Boer found the 201 vitamin D deficient Black patients were more likely, not less likely, to develop such plaque than the Whites were.”