Matti Nark
Sun, Mar-11-07, 06:15
The study
Hypponen E, Power C. Hypovitaminosis D in British adults at
age 45 y: nationwide cohort study of dietary and lifestyle
predictors. Am J Clin Nutr. 2007 Mar;85(3):860-8. PMID:
17344510 [PubMed - in process]
<http://www.ajcn.org/cgi/content/abstract/85/3/860>
published in the latest issue of AJCN investigated vitamin D
status (serum calcidiol a.k.a (25(OH)D concentrations) of
British adults at age 45 and found that the prevalence of
hypovitaminosis D was alarmingly high during the winter and
spring. Below the abstract of the study:
"BACKGROUND: Increased awareness of the importance of
vitamin D to health has led to concerns about the
prevalence of hypovitaminosis D in many parts of the
world. OBJECTIVES: We aimed to determine the prevalence of
hypovitaminosis D in the white British population and to
evaluate the influence of key dietary and lifestyle risk
factors. DESIGN: We measured 25- hydroxyvitamin D
[25(OH)D] in 7437 whites from the 1958 British birth
cohort when they were 45 y old. RESULTS: The prevalence of
hypovitaminosis D was highest during the winter and
spring, when 25(OH)D concentrations <25, <40, and <75
nmol/L were found in 15.5%, 46.6%, and 87.1% of
participants, respectively; the proportions were 3.2%,
15.4%, and 60.9%, respectively, during the summer and
fall. Men had higher 25(OH)D concentrations, on average,
than did women during the summer and fall but not during
the winter and spring (P = .006, likelihood ratio test for
interaction). 25(OH)D concentrations were significantly
higher in participants who used vitamin D supplements or
oily fish than in those who did not (P < 0.0001 for both)
but were not significantly higher in participants who
consumed vitamin D-fortified margarine than in those who
did not (P = 0.10). 25(OH)D concentrations <40 nmol/L were
twice as likely in the obese as in the nonobese and in
Scottish participants as in those from other parts of
Great Britain (ie, England and Wales) (P < 0.0001 for
both). CONCLUSION: Prevalence of hypovitaminosis D in the
general population was alarmingly high during the winter
and spring, which warrants action at a population level
rather than at a risk group level."
In the same issue of AJCN there is a Dutch vitamin D study
van Dam RM, Snijder MB, Dekker JM, Stehouwer CD, Bouter LM,
Heine RJ, Lips P. Potentially modifiable determinants of
vitamin D status in an older population in the Netherlands:
the Hoorn Study. Am J Clin Nutr. 2007 Mar;85(3):755-761. PMID:
17344497 [PubMed - as supplied by publisher]
<http://www.ajcn.org/cgi/content/abstract/85/3/755>,
which found that low vitamin D status among elderly people is
very common also in Holland. Here's its abstract:
"BACKGROUND: Inadequate vitamin D status is common in many
populations around the world. OBJECTIVE: The aim was to
evaluate potentially modifiable determinants of vitamin D
status in an older population. DESIGN: This was a cross-
sectional study from a population-based cohort including
538 white Dutch men and women aged 60-87 y. Vitamin D
status was assessed by plasma 25-hydroxyvitamin D
[25(OH)D] concentrations. RESULTS: In the winter period,
51% of the subjects had 25(OH)D concentrations <50.0
nmol/L. Greater body fatness and less time spent on
outdoor physical activity were associated with worse
vitamin D status. Regular use of vitamin D-fortified
margarine products [odds ratio (OR) in a comparison of
intake of >/=20 g/d with none: 0.41; 95% CI: .20, 0.86; P
for trend < 0.001], fatty fish (OR for servings of >/=2/mo
versus none: 0.41; 95% CI: 0.16, 1.04; P for trend
= .01), and vitamin D-containing supplements (OR for >/=
= 1/d
versus none: 0.33; 95% CI: 0.17, 0.63; P for trend <
0.001) were inversely associated with vitamin D
inadequacy [25(OH)D
<50. nmol/L]. We estimated that combined use of margarine
products (20 g/d), fatty fish (100 g/wk), and vitamin
D supplements (>/=1/d) was associated with a 16.8
nmol/L higher 25(OH)D concentration than was the use
of none of these. However, none of the participants
reached these intakes for all 3 factors. CONCLUSION:
Because few foods are vitamin D- fortified and the
amounts of vitamin D in supplements are low, it is
difficult to achieve adequate vitamin D status
through increasing intakes in the Netherlands and in
countries with similar policies."
The editorial of the same issue,
Vieth R, Bischoff-Ferrari H, Boucher BJ, Dawson-Hughes B,
Garland CF, Heaney RP, Holick MF, Hollis BW, Lamberg-Allardt
C, McGrath JJ, Norman AW, Scragg R, Whiting SJ, Willett WC,
Zittermann A. The urgent need to recommend an intake of
vitamin D that is effective. Am J Clin Nutr. 2007
Mar;85(3):649-50. PMID: 17344484 [PubMed - in process]
<http://www.ajcn.org/cgi/content/full/85/3/649>,
whose list of authors is packed with the most famous and
appreciated vitamin D researchers and also includes Harvard's
Walter C. Willett, comments the study by Hyppönen and Power,
states the urgent need to raise vitamin D recommendations,
and appeals to the authorities and other policy makers,
media, vitamin manufacturers, etc., to work for this goal to
get that done as soon as possible. Below a couple of excerpts
from this article:
"The report by Hyppönen and Power in this issue of the
Journal (1) highlights a frustrating and regrettable
situation for nutrition researchers. In the early 1970s,
the same serum 25-hydroxyvitamin D [25(OH)D]
concentrations reported by Hyppönen and Power were thought
to be indicative of "healthy" white adults in the United
Kingdom (2). However, during those early years after the
discovery of 25(OH)D, the adequacy of its serum
concentration was based simply on whether the
concentration was enough to prevent osteomalacia or
rickets. Three decades later, we know that 25(OH)D
concentrations relate to many other aspects of health,
including fracture risk, bone density, colon cancer, and
even tooth attachment (3); we also know that much higher
concentrations of 25(OH)D are needed to prevent adverse
outcomes. Indeed, in the 1958 British birth cohort, lower
25(OH)D is associated with a higher percentage of
hemoglobin
A1C (ameasure of long-term glucose concentration), which
further emphasizes the need to maintain optimal
25(OH)D concentrations (4).
[...]
It is important for major journals such as the AJCN to
publish evidence of a widespread nutrient deficiency.
Regrettably, we are now stuck in a revolving cycle of
publications that are documenting the same vitamin D
inadequacy (1-3, 5, 7-9, 13-17). This phenomenon has been
referred to as "circular epidemiology" (18), and, for
vitamin D, the phenomenon will continue for as long as the
levels of vitamin D fortification and supplementation and
the practical advice offered to the public remain
essentially the same as they were in the era before we
knew that 25(OH)D even existed. As scientists, the purpose
of our work is to improve the health of the public. We
know the realities of serum 25(OH)D concentrations in
populations around the world, and we have come to the
conclusion that public health will benefit from improved
vitamin D nutritional status. We know the intakes of
vitamin D needed to bring about desirable 25(OH)D
concentrations, so why is the science not making a
difference to public health? A major reason is that there
is little public pressure on policy makers to support
efforts to update recommendations about nutrition. Public
pressure is generally rooted in the media, but we do not
think that the public media present the vitamin D story in
a complete and accurate manner. Reports about vitamin D
inadequacies are presented straightforwardly, but, when it
comes to discussing the intake of vitamin D needed to
correct the situation, outdated official recommendations
for vitamin D are propagated by the public media. This
probably occurs because of restrictive editorial policies
driven by concern about possible litigation if media were
to advise a "toxic" intake greater than the UL. The
unfortunate result is that there is minimal motivation for
policy makers to implement the relatively simple steps
that could correct this nutrient deficiency.
Because of the convincing evidence for benefit and the
strong evidence of safety, we urge those who have the
ability to support public health - the media, vitamin
manufacturers, and policy makers - to undertake new
initiatives that will have a realistic chance of making a
difference in terms of vitamin D nutrition. We call for
international agencies such as the Food and Nutrition
Board and the European Commission's Health and Consumer
Protection Directorate-General to reassess as a matter of
high priority their dietary recommendations for vitamin D,
because the formal nationwide advice from health agencies
needs to be changed."
--
Matti Narkia
Hypponen E, Power C. Hypovitaminosis D in British adults at
age 45 y: nationwide cohort study of dietary and lifestyle
predictors. Am J Clin Nutr. 2007 Mar;85(3):860-8. PMID:
17344510 [PubMed - in process]
<http://www.ajcn.org/cgi/content/abstract/85/3/860>
published in the latest issue of AJCN investigated vitamin D
status (serum calcidiol a.k.a (25(OH)D concentrations) of
British adults at age 45 and found that the prevalence of
hypovitaminosis D was alarmingly high during the winter and
spring. Below the abstract of the study:
"BACKGROUND: Increased awareness of the importance of
vitamin D to health has led to concerns about the
prevalence of hypovitaminosis D in many parts of the
world. OBJECTIVES: We aimed to determine the prevalence of
hypovitaminosis D in the white British population and to
evaluate the influence of key dietary and lifestyle risk
factors. DESIGN: We measured 25- hydroxyvitamin D
[25(OH)D] in 7437 whites from the 1958 British birth
cohort when they were 45 y old. RESULTS: The prevalence of
hypovitaminosis D was highest during the winter and
spring, when 25(OH)D concentrations <25, <40, and <75
nmol/L were found in 15.5%, 46.6%, and 87.1% of
participants, respectively; the proportions were 3.2%,
15.4%, and 60.9%, respectively, during the summer and
fall. Men had higher 25(OH)D concentrations, on average,
than did women during the summer and fall but not during
the winter and spring (P = .006, likelihood ratio test for
interaction). 25(OH)D concentrations were significantly
higher in participants who used vitamin D supplements or
oily fish than in those who did not (P < 0.0001 for both)
but were not significantly higher in participants who
consumed vitamin D-fortified margarine than in those who
did not (P = 0.10). 25(OH)D concentrations <40 nmol/L were
twice as likely in the obese as in the nonobese and in
Scottish participants as in those from other parts of
Great Britain (ie, England and Wales) (P < 0.0001 for
both). CONCLUSION: Prevalence of hypovitaminosis D in the
general population was alarmingly high during the winter
and spring, which warrants action at a population level
rather than at a risk group level."
In the same issue of AJCN there is a Dutch vitamin D study
van Dam RM, Snijder MB, Dekker JM, Stehouwer CD, Bouter LM,
Heine RJ, Lips P. Potentially modifiable determinants of
vitamin D status in an older population in the Netherlands:
the Hoorn Study. Am J Clin Nutr. 2007 Mar;85(3):755-761. PMID:
17344497 [PubMed - as supplied by publisher]
<http://www.ajcn.org/cgi/content/abstract/85/3/755>,
which found that low vitamin D status among elderly people is
very common also in Holland. Here's its abstract:
"BACKGROUND: Inadequate vitamin D status is common in many
populations around the world. OBJECTIVE: The aim was to
evaluate potentially modifiable determinants of vitamin D
status in an older population. DESIGN: This was a cross-
sectional study from a population-based cohort including
538 white Dutch men and women aged 60-87 y. Vitamin D
status was assessed by plasma 25-hydroxyvitamin D
[25(OH)D] concentrations. RESULTS: In the winter period,
51% of the subjects had 25(OH)D concentrations <50.0
nmol/L. Greater body fatness and less time spent on
outdoor physical activity were associated with worse
vitamin D status. Regular use of vitamin D-fortified
margarine products [odds ratio (OR) in a comparison of
intake of >/=20 g/d with none: 0.41; 95% CI: .20, 0.86; P
for trend < 0.001], fatty fish (OR for servings of >/=2/mo
versus none: 0.41; 95% CI: 0.16, 1.04; P for trend
= .01), and vitamin D-containing supplements (OR for >/=
= 1/d
versus none: 0.33; 95% CI: 0.17, 0.63; P for trend <
0.001) were inversely associated with vitamin D
inadequacy [25(OH)D
<50. nmol/L]. We estimated that combined use of margarine
products (20 g/d), fatty fish (100 g/wk), and vitamin
D supplements (>/=1/d) was associated with a 16.8
nmol/L higher 25(OH)D concentration than was the use
of none of these. However, none of the participants
reached these intakes for all 3 factors. CONCLUSION:
Because few foods are vitamin D- fortified and the
amounts of vitamin D in supplements are low, it is
difficult to achieve adequate vitamin D status
through increasing intakes in the Netherlands and in
countries with similar policies."
The editorial of the same issue,
Vieth R, Bischoff-Ferrari H, Boucher BJ, Dawson-Hughes B,
Garland CF, Heaney RP, Holick MF, Hollis BW, Lamberg-Allardt
C, McGrath JJ, Norman AW, Scragg R, Whiting SJ, Willett WC,
Zittermann A. The urgent need to recommend an intake of
vitamin D that is effective. Am J Clin Nutr. 2007
Mar;85(3):649-50. PMID: 17344484 [PubMed - in process]
<http://www.ajcn.org/cgi/content/full/85/3/649>,
whose list of authors is packed with the most famous and
appreciated vitamin D researchers and also includes Harvard's
Walter C. Willett, comments the study by Hyppönen and Power,
states the urgent need to raise vitamin D recommendations,
and appeals to the authorities and other policy makers,
media, vitamin manufacturers, etc., to work for this goal to
get that done as soon as possible. Below a couple of excerpts
from this article:
"The report by Hyppönen and Power in this issue of the
Journal (1) highlights a frustrating and regrettable
situation for nutrition researchers. In the early 1970s,
the same serum 25-hydroxyvitamin D [25(OH)D]
concentrations reported by Hyppönen and Power were thought
to be indicative of "healthy" white adults in the United
Kingdom (2). However, during those early years after the
discovery of 25(OH)D, the adequacy of its serum
concentration was based simply on whether the
concentration was enough to prevent osteomalacia or
rickets. Three decades later, we know that 25(OH)D
concentrations relate to many other aspects of health,
including fracture risk, bone density, colon cancer, and
even tooth attachment (3); we also know that much higher
concentrations of 25(OH)D are needed to prevent adverse
outcomes. Indeed, in the 1958 British birth cohort, lower
25(OH)D is associated with a higher percentage of
hemoglobin
A1C (ameasure of long-term glucose concentration), which
further emphasizes the need to maintain optimal
25(OH)D concentrations (4).
[...]
It is important for major journals such as the AJCN to
publish evidence of a widespread nutrient deficiency.
Regrettably, we are now stuck in a revolving cycle of
publications that are documenting the same vitamin D
inadequacy (1-3, 5, 7-9, 13-17). This phenomenon has been
referred to as "circular epidemiology" (18), and, for
vitamin D, the phenomenon will continue for as long as the
levels of vitamin D fortification and supplementation and
the practical advice offered to the public remain
essentially the same as they were in the era before we
knew that 25(OH)D even existed. As scientists, the purpose
of our work is to improve the health of the public. We
know the realities of serum 25(OH)D concentrations in
populations around the world, and we have come to the
conclusion that public health will benefit from improved
vitamin D nutritional status. We know the intakes of
vitamin D needed to bring about desirable 25(OH)D
concentrations, so why is the science not making a
difference to public health? A major reason is that there
is little public pressure on policy makers to support
efforts to update recommendations about nutrition. Public
pressure is generally rooted in the media, but we do not
think that the public media present the vitamin D story in
a complete and accurate manner. Reports about vitamin D
inadequacies are presented straightforwardly, but, when it
comes to discussing the intake of vitamin D needed to
correct the situation, outdated official recommendations
for vitamin D are propagated by the public media. This
probably occurs because of restrictive editorial policies
driven by concern about possible litigation if media were
to advise a "toxic" intake greater than the UL. The
unfortunate result is that there is minimal motivation for
policy makers to implement the relatively simple steps
that could correct this nutrient deficiency.
Because of the convincing evidence for benefit and the
strong evidence of safety, we urge those who have the
ability to support public health - the media, vitamin
manufacturers, and policy makers - to undertake new
initiatives that will have a realistic chance of making a
difference in terms of vitamin D nutrition. We call for
international agencies such as the Food and Nutrition
Board and the European Commission's Health and Consumer
Protection Directorate-General to reassess as a matter of
high priority their dietary recommendations for vitamin D,
because the formal nationwide advice from health agencies
needs to be changed."
--
Matti Narkia