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									      LOW PREVALENCE                   OF     VITAMIN D DEFICIENCY                    IN    ELDERLY AFRO-CARIBBEAN MEN
Vitamin D deficiency is highly prevalent                        Iva Miljkovic, MD, PhD; Lisa M. Bodnar, PhD, MPH;
worldwide, and is linked to several major                             Jane A. Cauley, DrPH; Clareann H. Bunker, PhD;
chronic, inflammatory and autoimmune dis-
eases. Vitamin D deficiency has not been                Alan L. Patrick, MD, FRCP; Victor W. Wheeler, MBBS, FRCP;
evaluated in dark skinned individuals living in                  Lewis H. Kuller, MD, DrPH; Joseph M. Zmuda, PhD
areas of high sun exposure utilizing more
reliable mass spectrometry assay techniques.
We determined the prevalence of 25-hy-
droxyvitamin D (25(OH)D) deficiency in Af-
                                                  INTRODUCTION                                  there is high sun exposure, and among
ro-Caribbean men on the tropical island of
                                                                                                elderly men.
Tobago, where there is a high level of sunshine       Vitamin D is best known for its               The validity of earlier studies of
year round. Serum 25(OH)D2 and 25(OH)D3           role in maintaining calcium homeosta-         25(OH)D have been questioned due to
metabolites were measured following extrac-                                                     the use of insensitive and unreliable
                                                  sis and skeletal integrity, although
tion and purification using liquid chromatog-
                                                  vitamin D is also critical for maintain-      radioimmunoassay-based methods
raphy and tandem mass spectrometry in 424
Afro-Caribbean men aged .65 years from a          ing the health and function of the            which were fraught with inaccuracies
larger population-based cohort study. The         immune, reproductive, and muscular            due in part to protein binding arti-
mean (6SD) serum total 25(OH)D concentra-         systems.1 Vitamin D status is largely         facts.15,16 Improvements in assay meth-
tion was 35.1 6 8.9 ng/mL. Deficiency                                                           ods, such as liquid chromatography
                                                  determined by cutaneous synthesis
(,20 ng/mL) was present in only 2.8% and
                                                  from solar exposure and dietary sources       tandem mass-spectrometry (LC-MS/
insufficiency (,30 ng/mL) in 24% of the men.
Multiple linear regression analysis identified    and is assessed by measuring circulat-        MS) and high performance liquid
age, BMI and daily vitamin D supplementation      ing levels of 25-hydroxyvitamin D             chromatography, have enabled the di-
as the independent correlates of 25(OH)D.         (25(OH)D). However, in free-living            rected detection of the D2 (ergocalcif-
None of the men who consumed fish more                                                          erol) and D3 (cholecalciferol) metabo-
                                                  individuals, the majority of circulating
than once per week had vitamin D deficiency,                                                    lites and are considered preferred
compared to 4% of the men who consumed
                                                  25(OH)D originates from UVB expo-
fish once per week or less (P5.01, adjusted for   sure. Epidemiologic studies have              techniques for assessing nutritional vi-
age, BMI, and daily vitamin D supplementa-        linked low 25(OH)D with obesity,2             tamin D status.15,16
tion). In conclusion, vitamin D deficiency is     type 2 diabetes,3,4 cancer,5 cardiovas-           In our study, we measured 25(OH)D,
very uncommon in this Afro-Caribbean popu-                                                      25(OH)D2 and 25(OH)D3 using LC-
                                                  cular disease,6,7 and infectious8 and
lation. Longitudinal studies are needed to                                                      MS/MS in elderly African ancestry men
delineate the possible effects of high vitamin
                                                  autoimmune diseases.1
D levels in this population on major diseases         The mean concentration of 25(OH)D         living in Tobago. Tobago (latitude
hypothesized to be associated with vitamin D      is generally lower among the elderly          11uN) is a Caribbean island, located in
deficiency. (Ethn Dis. 2011;21:79–84)             and among dark skinned individuals.9          the West Indies, between the Caribbean
                                                  Individuals of African ancestry living        Sea and the North Atlantic Ocean,
Key Words: Vitamin D, 25(OH)D, Afro-                                                            northeast of Venezuela. We examined
Caribbean, Tobago, Men                            in the United States typically have
                                                  lower levels of serum 25(OH)D than            the prevalence of vitamin D deficiency
                                                  Caucasians across all age groups and          and also determined the impact of several
                                                  both sexes due at least in part to            potential correlates of serum 25(OH)D
                                                  differences in skin pigmentation and          in this population.
                                                  dietary vitamin D intake.9–13 Vitamin
                                                  D status in African ancestry individuals
                                                  has been primarily assessed in healthy        DESIGN AND METHODS
                                                  younger individuals, pregnant and lac-
    From Department of Epidemiology,              tating women, healthy children and            Study Population
Graduate School of Public Health, Pitts-          those with rickets, and clinical studies          Between 1997 and 2003, 3170
burgh, University of Pittsburgh, Pennsylva-       of tuberculosis and pneumonia pa-             previously unscreened men were recruit-
nia (IM, LMB, JAC, CHB, LHK, JMZ) and
Tobago Health Studies Office, Scarborough,        tients.14 A recent review of studies in       ed for a population-based prostate
Tobago, Trinidad & Tobago (ALP, VWW).             the African continent has shown that          cancer screening study on the Caribbean
                                                  vitamin D status varies considerably          Island of Tobago, Trinidad and To-
     Address correspondence to Iva Miljko-        depending on geography, climate, and          bago.17 To be eligible, men had to be
vic, MD, PhD; Department of Epidemiolo-           other factors.14 However, there is insuf-     ambulatory, non-institutionalized and
gy, Center for Aging and Population Health;
University of Pittsburgh; 130 North Belle-        ficient data in African ancestry individ-     not terminally ill. Recruitment for the
field Ave, Room 542; Pittsburgh, PA 15213;        uals living in other geographic regions,      survey was accomplished by flyers,
412.383.1894;             particularly in tropical climates where       public service announcements, posters,

                                                  Ethnicity & Disease, Volume 21, Winter 2011                                         79

                                            and 25(OH)D3 were performed at the              Obesity was defined as BMI $30, and
We examined the prevalence                  Mayo Clinic using samples that had not          type 2 diabetes was defined as fasting
                                            been previously thawed.18 Deuterated            serum glucose $126mg/dL or currently
of vitamin D deficiency and                 stable isotope (d3-25-hydroxyvitamin            taking anti-diabetic medication.19 Alco-
also determined the impact of               D) was added to a .2-mL serum sample            hol drinking frequency (never, less than
                                            as an internal standard. 25 (OH)D3 and          one drink per week, 1–3, 4–7, 8–14,
several potential correlates of             25 (OH)D2 and the internal standard             15–21, 22–27, $28, drinks per week)
serum 25(OH)D in African                    were extracted using acetonitrile precip-       and hours of TV watching, as a measure
                                            itation. The extracts were then further         of sedentary lifestyle, (0, 1–6, 7–13, 14–
ancestry men living in                      purified on-line utilizing high turbu-          20, 21–27, $28, hours of TV watching
                                            lence liquid chromatography (HTLC).             per week) were self-reported in prede-
Tobago.                                     This was followed by conventional               fined categories. Fish and milk intake
                                            liquid chromatography and analysis on           frequency were also self-reported in
                                            a tandem mass spectrometer (LC-MS/              predefined categories (never, a few times
informing health care workers at local      MS) equipped with a heated nebulizer            per year, 1 time per month, 2–3 times
hospital and health centers, and word of    ion source and operated in the multiple-        per month, 1 time per week, 2 times per
mouth. Approximately 60% of all age-        reaction monitoring positive mode. The          week, 3–4 times per week, 5–6 times
eligible men on the island participated     calibration utilized a six point standard       per week, every day). We arbitrarily
and participation was similar across the    curve over a concentration range of 0–          created two categories of fish, milk and
island Parishes. All men were invited to    200 ng/mL. The minimum detectable               alcohol use (#1 and .1 once per week)
participate in a follow-up clinic exam      limit for 25(OH)D2 was 4 ng/mL and              and two categories of TV viewing (,14
between 2004 and 2007 and 2,031 men         for 25(OH)D3 was 2 ng/mL.                       and $14 hours/week)
in the cohort (70% of survivors) and        25(OH)D2 and 25(OH)D3 were quan-
451 new participants completed the          tified, reported individually and summed        Statistical Analyses
visit. Approximately 89% of the men         for total 25(OH)D. Using the pooled                 The distributions of 25(OH)D,
at the follow-up visit reported that both   serum, the inter-assay CV for 25(OH)D2          25(OH)D3 and detectable 25(OH)D2
paternal and maternal grandparents          was 6.1% and the intra-assay CV was             levels were approximately normal. Sea-
were of African ethnicity. There were       4.4%, whereas the inter-assay CV for            son of visit was coded as winter
618 Afro-Caribbean men aged $65             25(OH)D3 was 6.4% and the intra-assay           (January–March), spring (April–June),
years (with all 4 grandparents of African   CV was 3.8%. Deficiency was defined as          summer (July–September), and fall
ancestry). Vitamin D was measured in a      total 25(OH)D ,20 ng/mL, insufficien-           (October–December). Using linear re-
random subset of 500 of these men. The      cy as 20–29 ng/mL and sufficiency as 30–        gression analysis, we first evaluated the
present analysis is limited to 424 men      149 ng/mL.1 No participant had toxic            age-adjusted association of each mea-
who had complete anthropometry, de-         levels (. 150 ng/mL).                           sured risk factor with 25(OH)D. The
mographic information, and medical                                                          relationships between potential corre-
history. Written informed consent was       Potential Correlates of 25(OH)D                 lates and 25(OH)D were expressed as
obtained from all study participants            We tested several potential correlates      one unit for categorical variables or 1
using forms approved by the Institu-        of 25(OH)D that were available in our           SD for continuous variables, along with
tional Review Boards of the University      study. Body mass index was calculated           95% confidence intervals (CIs). To
of Pittsburgh and the Tobago Division       from height and weight (kg/m2). Height          identify the independent correlates of
of Health and Social Services.              was measured to the nearest .1 cm using         25(OH)D, multiple linear regression
                                            a wall-mounted stadiometer. Body                analysis with backwards elimination of
Measurement of 25(OH)D                      weight was recorded to the nearest              the least significant variable was per-
    Blood for vitamin D analysis was        .1 kg without shoes on a balance beam           formed separately. Variables with
collected at the follow-up visit, in the    scale. Waist circumference was mea-             P,.10 in the age-adjusted univariate
morning after an overnight fast using       sured at the narrowest point of the waist       linear regression model were entered
red-top tubes that did not contain any      using an inelastic fiberglass tape. Infor-      into the multiple variable model. The
additives. Samples were allowed to clot     mation on lifestyle habits, demographic         Statistical Analysis System (SAS, version
at room temperature, the serum sepa-        information, medical conditions (type 2         9.1.2.; SAS Institute, Cary, NC) and
rated and then frozen at 280C until         diabetes and hypertension), and medi-           the Statistical Package for the Social
shipment on dry ice to the University of    cation use were assessed using inter-           Sciences (SPSS, version 16; Chicago,
Pittsburgh. Measures for 25(OH)D2           viewer administered questionnaires.             IL) were used for statistical analysis.

80                                            Ethnicity & Disease, Volume 21, Winter 2011
                                                                                  VITAMIN D DEFICIENCY IN TOBAGO - Miljkovic et al

Table 1. General characteristics and correlates of total 25(OH)D in Afro-Caribbean men (N=424)

                                                                                          Age-adjusted                   Multivariable model
                                                       Mean (±SD) or
                 Variable                          frequency (prevalence)              Absolute difference in 25(OH)D Levels per SD (95%CI)
Age, yrs3                                               72.1 6 5.8                     2.96   (21.8, 2.1)*              21.33 (22.2, 2.5)*
BMI, kg/m2                                              26.8 6 4.3                     21.8   (22.7,2.97)*               21.8 (22.6,2.9)*
Waist circumference, cm                                 93.1 6 11.5                    21.2   (22.0,2.38)*                       -
Time spent walking in the past week , min               56.6 6 58.4                    29.0   (2173, 231)                        -
TV watching $14 hours per week, %                           32.9                       21.1   (22.9, .7)                         -
Currently smoke, %                                           5.7                       22.5   (26.2, 1.2)                        -
.1 drinks per week, %                                       14.9                        2.1   (22.5, 2.3)                        -
Milk intake .once per week, %                               70.7                       21.1   (22.9, .7)                         -
Fish intake .once per week, %                               28.5                        .92   (2.97, 2.8)                        -
Daily vitamin D supplement use, %                            8.1                        2.4   (2.75, 2.05)*              2.38 (20.73, 2.03)*
Vitamin D sufficiency, %4                                   73.1                                  -
Vitamin D insufficiency, %1                                 24.1                                  -
Vitamin D deficiency, %I                                     2.8                                  -
25(OH)D-total, ng/mL                                    35.1 6 8.9                                -
25(OH) D2, if detectable, ng/mL                          5.7 6 2.9                                -
25(OH) D3, ng/mL                                        34.7 6 8.8                                -
 * P,.05
 3 Unadjusted.
 4 Total 25-hydroxyvitamin D levels $30 ng/mL.
 1 Total 25-hydroxyvitamin D levels ,20 ng/mL.
 I Total 25-hydroxyvitamin D levels 20–29 ng/mL.

RESULTS                                               25(OH)D. The daily use of vitamin D                 smoked, drank more than one alcoholic
                                                      supplements was also negatively associ-             drink per week, watched TV for 14 or
    The mean age of the men was                       ated with 25(OH)D levels. No other                  more hours per week (data not shown).
72 years, range 65–92 years (Table 1).                variables were significantly correlated                 There was no significant difference
The average serum total 25(OH)D level                 with 25(OH)D. To identify the inde-                 in serum 25(OH)D levels between those
was 35.1 6 8.9 ng/mL. Almost all                      pendent correlates of 25(OH)D, we                   who reported vitamin D supplement
circulating 25(OH)D was derived from                  further tested age, BMI, waist circum-              intake and those who did not (age- and
vitamin D3; only 8% had 25(OH)D2                      ference, and daily vitamin D supple-                BMI-adjusted P5.08), or in the preva-
in the detectable range (.4 ng/mL),                   ment use in the multiple linear regres-             lence of vitamin D insufficiency (age-
and mean 25(OH)D2 levels were low                     sion model. Age, BMI and daily vitamin              and BMI-adjusted P5.055) and vita-
(5.7 6 2.9 ng/mL) among men with                      D supplement use remained significant,              min D deficiency between vitamin D
detectable levels. Vitamin D insufficien-             independent correlates of 25(OH)D                   supplement users and non-users (age-
cy was observed in 24% whereas                        (Table 1), and collectively explained               and BMI-adjusted P5.98).
vitamin D deficiency was observed in                  6% of the variation in 25(OH)D.                         The difference in serum 25(OH)D
only 2.8% of the men. Fish intake was                     Although fish intake was not associ-            levels between seasons was small and not
relatively frequent with almost 29%                   ated with mean levels of 25(OH)D,                   statistically significant (age- and BMI-
reporting that they ate fish (with meat               none of the men who ate fish $1 times               adjusted P5.25). Mean total 25(OH)D
and bones) more than once per week                    per week had vitamin D deficiency,                  levels were highest in fall (36.2 6
and 17.5% reporting that they ate fish 3              whereas the 4% who consumed fish less               8.7 ng/mL) compared to winter (34.6
or more times per week. The daily use                 than once per week had vitamin D                    6 9.6 ng/mL), spring (34.5 6 8.8 ng/
of vitamin D supplements was very low                 deficiency (P5.01, adjusted for age,                mL) and summer (34.4 6 8.1 ng/mL).
(8.1%). 18.6% of the men were obese                   BMI, and daily vitamin D supplement).
and 36% had type 2 diabetes.                          The prevalence of vitamin D insuffi-
    In age-adjusted regression analyses               ciency was similar in both groups                   DISCUSSION
each SD (4.3 kg/m2) increase in BMI                   (P5.80, adjusted for age, BMI, and
was associated with 1.8% lower                        daily vitamin D supplement). No                         We found a very low prevalence of
25(OH)D (Table 1). In addition, every                 difference in prevalence of deficiency              vitamin D deficiency among older men
11.5cm increase in waist circumference                and insufficiency was observed among                of African ancestry in Tobago. Tobago,
was associated with 1.2% lower                        those who drank more milk, currently                located at 11 degrees north latitude,

                                                      Ethnicity & Disease, Volume 21, Winter 2011                                              81

experiences a tropical climate and is     children, women, and tuberculosis and
sunny all year. The average annual        pneumonia patients.14 However, the              Levels of 25(OH)D2 were
daytime temperature is 29uC (83uF).       prevalence of vitamin D deficiency in
There is a short rainy season from June   the African continent varies widely, in         undetectable in most of the
until the end of October, but there are   line with a geographical gradient, and          men in our study suggesting
periods of sunshine between the epi-      25(OH)D seems to be much lower in
sodes of very short but heavy rainfall.   North African countries and in South            that many older Afro-
The adult dress does not restrict         Africa compared with tropical African           Caribbean men have minimal
sunshine exposure of the arms, face, or   countries.14 Interestingly, in the north-
head. The high year-round sun exposure    western African country of Gambia with          exposure to vitamin D2.
is a likely explanation for the low       latitude similar as Tobago (13uN), the
prevalence of vitamin D deficiency in     mean 25(OH)D level (25.7 ng/mL)
this population.                          among healthy men aged 60–64 years,
    Previous studies have shown that      was higher than reported levels for             in adipocytes.29 Enhanced lipogenesis
African Americans typically have lower    African-Americans, but still slightly           and reduced lipolysis in African ancestry
levels of serum 25(OH)D than Cauca-       lower than levels in our study.24               individuals may also lead to their greater
sian Americans.9–13 The mean levels of         Levels of 25(OH)D2 were undetect-          ability to sequester vitamin D in
total 25(OH)D among Afro-Caribbean        able in most of the men in our study            adipocytes than Caucasians.30 Although
men in our study (35 ng/mL) were          suggesting that many older Afro-Carib-          the possible mechanisms linking vita-
considerably higher than the levels       bean men have minimal exposure to               min D and accumulation of fat are still
among older African American men in       vitamin D2. Although we did not                 unclear, a recently study has proposed a
the Third National Health and Nutri-      attempt to assess dietary intake of             novel aspect of vitamin D biology in
tion Examination Survey (NHANES           vitamin D from food, very few men               regulation of energy metabolism.31
III) (17 ng/mL) and among older           (8.1%) in our study reported daily use          Wong et al have reported that in
African American men in the Study of      of vitamin D supplements. We found              animals, vitamin D is involved in energy
Osteoporotic Fractures in Men (MrOS)      that daily use of vitamin D supplements         metabolism at least in part through the
(18.5 ng/mL).20,21 Additionally, in       is inversely associated with 25(OH)D in         regulation of b-oxidation in white
MrOS, 64% of African American men         our study, and insufficiency was higher         adipose tissue and direct suppression
and 23.3% of older Caucasian Ameri-       in supplement users than in non-users.          of the expression of UCP1 and UCP3
can men aged $65 years had vitamin D      However, typical vitamin D supplement           in brown adipose tissue.31
deficiency based on the same assay        doses are not generally thought to be               We identified a positive, but weak
methods and laboratory that we used.      adequate to ensure sufficient serum             association between fish intake and
These prevalences are considerably        25(OH)D levels.25 Holick et al recently         vitamin D deficiency in our population
higher than the prevalence (2.8%)         reported that for every 100 IU intake of        sample. Fish consumption is a signifi-
among the Afro-Caribbean men from         vitamin D2 or vitamin D3, there is a            cant factor in maintaining adequate
our study.                                very small increase in circulating              levels of serum 25(OH)D, and a
    The lower values of 25(OH)D in        25(OH)D levels of only 1 ng/mL.26               positive association between fish intake
black African ancestry individuals com-   This may explain in part why in our             and 25(OH)D was observed among
pared with Caucasians have been attrib-   study men reporting supplement use              active elderly Japanese men and women,
uted primarily to their darker skin       have lower serum 25(OH)D levels.                and healthy middle-aged Asian
pigmentation and insufficient cutaneous        We observed a negative and inde-           men.32,33 We are unaware of studies
synthesis of 25(OH)D.22 Lower con-        pendent association between BMI and             reporting an association between fish
sumption of dairy products and other      25(OH)D. Few studies have examined              intake and vitamin D status in African
foods fortified with vitamin D and        whether obesity is linked to lower serum        ancestry individuals, mainly because of
lower sun exposure are frequently cited   25(OH)D levels in African-Ameri-                their very low fish intake.34
as additional causes of the high preva-   cans.27,28 Some studies have shown a                The present study has several poten-
lence of vitamin D deficiency in black    weaker inverse correlation between              tial limitations. Demographic and life-
African ancestry individuals.23 Epide-    25(OH)D and obesity in African-Amer-            style information was self-reported and
miologic data on vitamin D in African     icans compared to Caucasians of the             may be subject to misclassification.
countries has been limited and mainly     same age.27 Reduced serum levels of             Other potentially important factors
derived from populations at high risk     25(OH)D in obesity has been attributed          associated with 25(OH)D levels were
for deficiency, such as undernourished    to sequestration of fat soluble vitamin D       not assessed in our study including

82                                          Ethnicity & Disease, Volume 21, Winter 2011
                                                                                     VITAMIN D DEFICIENCY IN TOBAGO - Miljkovic et al

direct estimates of sunlight exposure,                    analysis. J Clin Endocrinol Metab. 2007;          18. Singh RJ, Taylor RL, Reddy GS, Grebe SK. C-
sun protection behaviors and dietary                      92(6):2017–2029.                                      3 epimers can account for a significant
                                                     5.   Garland CF, Gorham ED, Mohr SB, Garland               proportion of total circulating 25-hydroxyvi-
intake of vitamin D from food sources                                                                           tamin D in infants, complicating accurate
                                                          FC. Vitamin D for cancer prevention: global
other than fish and milk intake. How-                     perspective. Ann Epidemiol. 2009;19(7):               measurement and interpretation of vitamin D
ever, our study also had notable                          468–483.                                              status. J Clin Endocrinol Metab. 2006;91(8):
strengths including its reliance on a                6.   Giovannucci E, Liu Y, Hollis BW, Rimm EB.             3055–3061.
population-based sample of Afro-Carib-                    25-hydroxyvitamin D and risk of myocardial        19. Report of the Expert Committee on the
                                                          infarction in men: a prospective study. Arch          Diagnosis and Classification of Diabetes Mel-
bean men and the use of an accurate and
                                                          Intern Med. 2008;168(11):1174–1180.                   litus. Diabetes Care. 1997;20(7):1183–1197.
reliable LC-MS/MS method to measure                  7.   Michos ED, Melamed ML, Vitamin D,                 20. Ginde AA, Liu MC, Camargo CA Jr. Demo-
25(OH)D2 and 25(OH)D3 that was                            cardiovascular disease risk. Curr Opin Clin           graphic differences and trends of vitamin D
free of the artifacts that have affected                  Nutr Metab Care. 2008;11(1):7–12.                     insufficiency in the US population, 1988–
earlier radioimmunoassay based meth-                 8.   Yamshchikov AV, Desai NS, Blumberg HM,                2004. Arch Intern Med. 2009;169(6):626–632.
ods.16                                                    Ziegler TR, Tangpricha V. Vitamin D for           21. Orwoll E, Nielson CM, Marshall LM, et al.
                                                          treatment and prevention of infectious diseas-        Vitamin D deficiency in older men. J Clin
    In conclusion, vitamin D deficiency
                                                          es: a systematic review of randomized con-            Endocrinol Metab. 2009;94(4):1214–1222.
is very uncommon in the Afro-Carib-                       trolled trials. Endocr Pract. 2009;15(5):         22. Matsuoka LY, Wortsman J, Haddad JG, Kolm
bean male population of Tobago.                           438–449.                                              P, Hollis BW. Racial pigmentation and the
Future longitudinal studies are needed               9.   Zadshir A, Tareen N, Pan D, Norris K,                 cutaneous synthesis of vitamin D. Arch
to delineate the possible effects of high                 Martins D. The prevalence of hypovitaminosis          Dermatol. 1991;127(4):536–538.
serum 25(OH)D levels in this popula-                      D among US adults: data from the NHANES           23. Moore CE, Murphy MM, Holick MF.
                                                          III. Ethn Dis. 2005;15(4 Suppl 5):S5-97–S5-           Vitamin D intakes by children and adults in
tion on vitamin D related outcomes.                                                                             the United States differ among ethnic groups.
                                                    10.   Flegal KM, Carroll MD, Ogden CL, Johnson              J Nutr. 2005;135(10):2478–2485.
                                                          CL. Prevalence and trends in obesity among        24. Yan L, Schoenmakers I, Zhou B, et al. Ethnic
ACKNOWLEDGMENTS                                           US adults, 1999–2000. JAMA. 2002;288(14):             differences in parathyroid hormone secretion
Dr. Miljkovic was supported by the Men-                   1723–1727.                                            and mineral metabolism in response to oral
tored Research Scientist Development                11.   Brancati FL, Kao WH, Folsom AR, Watson                phosphate administration. Bone. 2009;45(2):
Award from the National Institute of                      RL, Szklo M. Incident type 2 diabetes mellitus        238–245.
Diabetes and Digestive and Kidney Diseases                in African American and white adults: the         25. Vieth R, Bischoff-Ferrari H, Boucher BJ, et al.
(K01-DK083029). Dr. Bodnar was support-                   Atherosclerosis Risk in Communities Study.            The urgent need to recommend an intake of
ed by the Mentored Research Scientist                     JAMA. 2000;283(17):2253–2259.                         vitamin D that is effective. Am J Clin Nutr.
Development Award from the National                 12.   Harris MI, Flegal KM, Cowie CC, et al.                2007;85(3):649–650.
Institute of Mental Health (K01-                          Prevalence of diabetes, impaired fasting glu-     26. Holick MF, Biancuzzo RM, Chen TC, et al.
MH074092). This research was supported,                   cose, and impaired glucose tolerance in U.S.          Vitamin D2 is as effective as vitamin D3 in
                                                          adults. The Third National Health and                 maintaining circulating concentrations of 25-
in part, by funding or in-kind services from
                                                          Nutrition Examination Survey, 1988–1994.              hydroxyvitamin D. J Clin Endocrinol Metab.
the Division of Health and Social Services
                                                          Diabetes Care. 1998;21(4):518–524.                    2008;93(3):677–681.
and Tobago House of Assembly, by grants
                                                    13.   Scragg R, Sowers M, Bell C. Serum 25-             27. Looker AC. Body fat and vitamin D status in
R03-AR050107 and R01-AR049747 from
                                                          hydroxyvitamin D, ethnicity, and blood                black versus white women. J Clin Endocrinol
the National Institute of Arthritis and
                                                          pressure in the Third National Health and             Metab. 2005;90(2):635–640.
Musculoskeletal and Skin Diseases, and by
                                                          Nutrition Examination Survey. Am J Hypertens.     28. Parikh SJ, Edelman M, Uwaifo GI, et al. The
grant R01-HD056999 from the National                      2007;20(7):713–719.                                   relationship between obesity and serum 1,25-
Institute of Child Health and Human                 14.   Prentice A, Schoenmakers I, Jones K, Jarjou L,        dihydroxy vitamin D concentrations in healthy
Development.                                              Goldberg G. Vitamin D deficiency and its              adults. J Clin Endocrinol Metab. 2004;89(3):
                                                          health consequences in Africa. Clinical Reviews       1196–1199.
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    vitamin D in the Japanese diet. Nutrition.     AUTHOR CONTRIBUTIONS                             Manuscript draft: Miljkovic, Bodnar, Cauley,
    2002;18(5):415–416.                                                                                 Bunker, Patrick, Wheeler, Kuller,
33. Lym YL, Joh HK. Serum 25-hydroxyvitamin        Design concept of study: Miljkovic, Bodnar,          Zmuda
    D3 is related to fish intake and exercise in       Cauley, Bunker, Patrick, Wheeler, Kul-       Statistical expertise: Miljkovic, Bodnar, Cau-
    Korean adult men. Asia Pac J Clin Nutr.            ler, Zmuda                                       ley, Bunker, Patrick, Wheeler, Kuller,
    2009;18(3):372–376.                            Acquisition of data: Miljkovic, Bodnar,              Zmuda
34. Gillum RF, Mussolino ME, Madans JH. Fish           Cauley, Bunker, Patrick, Wheeler, Kul-       Acquisition of funding: Miljkovic, Bodnar,
    consumption and hypertension incidence in          ler, Zmuda                                       Cauley, Bunker, Patrick, Wheeler, Kul-
    African Americans and whites: the NHANES I     Data analysis and interpretation: Miljkovic,         ler, Zmuda
    Epidemiologic Follow-up Study. J Natl Med          Bodnar, Cauley, Bunker, Patrick,             Supervision: Miljkovic, Bodnar, Cauley, Bun-
    Assoc. 2001;93(4):124–128.                         Wheeler, Kuller, Zmuda                           ker, Patrick, Wheeler, Kuller, Zmuda

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