Diagnosis and management of vitamin D deficiency

(We are re submitting this with the references)

We read with interest, the clinical review on vitamin D deficiency
and were reminded of the pressures we face from our local clinicians and
sometimes members of the public demanding a universal approach, especially
because our borough has a high ethnic mix. While we agree with the authors
regarding the clinical management of vitamin D deficiency, we cannot agree
with the authors’ recommendation that the public health approach needs to
be a universal supplementation (here universal means all pregnant women,
children and the elderly) or fortification of foods with vitamin D (Simon
H S Pearce, Tim d Cheetham. Diagnosis and management of vitamin D
deficiency. BMJ 2009;340:142-47).

Authors state that vitamin D deficiency is common in the UK. However,
there is no national data at population level to support this and most
prevalence studies are based on hospital data or on small samples.
Similarly the data on at risk groups such as the Asian population comes
from hospital based studies in areas with higher ethnic mix such as
Bradford and Birmingham.

Authors also state that 90% of vitamin D comes from sunlight and the
at risk population (dark skinned) needs up to a 10 fold increase in
exposure to sunlight compared to the light skinned population. If this is
entirely true, given the amount of sunlight exposure in South Asian
countries, one would expect the prevalence of vitamin D deficiency to be
considerably lower. But studies have shown that the prevalence of vitamin
D deficiency in South Asian counties is higher than in the UK at 50% and
above. Often this problem has been attributed to poor dietary intake and
calcium deficiency (Masood SH, Iqbal MP. Prevalence of vitamin D
deficiency in South Asia. Pak J Med Sci 2008;24(6): 891-97).

Some might attribute this to the practice of South Asian population
covering themselves fully. However, a study in India where 75% are Hindus
and 4% Christians who do not cover themselves and with sunscreen creams
not in common use showed that the prevalence in pregnant women was >80%
( Sachan A, Gupta R, Das V, Agarwal A, Pradeep K, Awasthi PK, et al. High
prevalence of vitamin D deficiency among pregnant women and their newborns
in northern India. Am J Clin Nutr 2005;81:1060-4)

The authors have discussed the DH’s guidance but have not discussed
the most recent NICE guidance on maternal and child nutrition which
supersedes the DH’s guidance (NICE. Maternal and Child Nutrition.
PH11.2008). NICE has looked into the evidence and has recommended the
issue of the healthy start vitamins to children aged 6 months to 4 years
and pregnant women who are eligible for income support. It also
recommends that all the frontline professionals should aim to promote the
benefits of vitamin D to all the pregnant women and children who are not
eligible for healthy start vitamins.

Supplementation of vitamin D without assessing the dietary intake (a
person may be identified as being ‘at risk’ because of his or her skin
colour, but may be taking plenty of fish and supermarket cereals which has
100% of the RDA) means that individuals are asked to take unnecessary
levels of vitamin D. Even though toxicity is known only at huge doses of
vitamin D intake, the risk of chronic toxicity has also been documented
(Leake CD. Vitamin D Toxicity. Cal West Med. 1936 Mar;44(3):149–150.)

We would also like to quote the most recent systematic review
published in August 2009 (Evidence Report/Technology Assessment Number 183
Vitamin D and Calcium: A Systematic Review of Health Outcomes) This
review included 165 studies and 11 systematic reviews and concluded that
the majority of the findings concerning vitamin D, calcium, or a
combination of both nutrients on the different health outcomes were
inconsistent. It also acknowledged that synthesising a dose-response
relationship between intake of either vitamin D, calcium, or both
nutrients and health outcomes in this heterogeneous body of literature was
challenging. It concluded that studies on the association between either
serum 25(OH)D concentration or calcium intake and other forms of cancer
(colorectal, pancreas, prostate, all-cause), incidence of hypertension or
specific cardiovascular disease events, immunologic disorders and
pregnancy-related outcomes including preeclampsia were either few in
number or reported inconsistent findings.

While vitamin D deficiency is unacceptable and should be treated
promptly, the evidence available so far and the magnitude of the problem
in the UK does not justify universal vitamin d supplementation or
fortification for the following reasons:

1. Apart from hospital based data and few small scale studies, there
is no national level data to show that vitamin D deficiency is increasing
at levels that makes it a public health priority.
2. While vitamin D deficiency in the high risk population has been
attributed to lack of sunlight in the UK, the even higher prevalence in
countries with excessive sunlight (and where people do not cover
themselves fully), has been attributed to poor dietary intake.

3. The evidence linking the different health problems and vitamin D
as an independent risk factor is inconclusive.

We strongly believe that the best strategy for the UK in the current
situation is that every front line health professionals provide
information on the benefits and sources of vitamin D and empower the
individuals to decide. After all, it is freely available to purchase in
the UK.

Competing interests:
None declared