This study addressed
the issue of the prevalence and the determinants of hypovitaminosis D
among 1,546 African American and 1,426 white women of reproductive age
(15-49). These women were not pregnant and participated in the Third
National Health and Nutrition Examination Survey (1988 – 1994).
Hypovitaminosis D was defined as serum 25-hydroxyvitamin D
concentrations of < 37.5 nmol/L. The prevalence of hypovitaminosis D
was 42.4% among African American women as compared to only 4.2% among
white women. The presence of hypovitaminosis D was independently
associated with low consumption of milk or cereal, less than ideal use
of vitamin D supplements, cold seasons, urban residence, low body mass
index, and use of oral contraceptives. Even among the 243 African
Americans who consumed an adequate intake of vitamin D from
supplements (>200 IU/d), 28.2% had hypovitaminosis D. The authors
concluded that the high prevalence of hypovitaminosis D among African
American women warrants further examination of the vitamin D
recommendations for these women. The determinants of hypovitaminosis
D among women should be considered when these women are advised
regarding dietary intake and supplement use.
Editor’s Comments:
The report by this group of investigators provided compelling data
with irrefutable evidence that vitamin D deficiency constitutes a
major unrecognized epidemic in many young black adult women and in 5%
of white women of childbearing age. This survey might have shown a
much higher prevalence of hypovitaminosis D if it had been performed
in the winter. We may also assume that vitamin D deficiency might be
equally prevalent among males of the same age and race, although this
was not studied. This article clearly documents it is still currently
possible to frequently find vitamin D deficiency in the United States,
which plagued our ancestors during the 19th century. There
are vulnerable populations, such as those who are not exposed to the
benefits of sunlight irradiation, and in those who are dark skinned.
The latter may not be able to synthesize sufficient vitamin D from the
skin to prevent vitamin D deficiency, and may be in need of higher
levels of vitamin D intake as compared to their white counterparts.
Therefore, the recommendation to examine the dietary recommendations
for young black women and men should be quickly undertaken. Since the
black population has a high incidence of lactase deficiency and,
therefore, not able to tolerate milk, oral vitamin D supplements may
be needed.
In this study there
were no measurements of parathyroid hormone levels or the active
metabolic vitamin D (25-D hydroxy vitamin D), both of which are very
sensitive indicators of calcium homeostasis and vitamin D deficiency.
The high prevalence of hypovitaminosis D among “healthy young female
adults” is important as vitamin D deficiency is associated with
osteomalacia, bone pain, muscle aches, muscle weakness, and
fibromyalgia. It also causes secondary hyperparathyroidism, which can
precipitate and exacerbate osteoporosis by increasing mobilization of
mineral and matrix from the skeleton. Therefore, there is reason for
each of us to pay attention to an easily remedied medical problem that
affects many of our patients whether they are adults or children.
Fima
Lifshitz, MD
