Bariatric surgeons are finding out that
they have problems in many patients that they have operated on and
this is the high risk of vitamin D deficiency and insufficiency among
bariatric surgery patients. Both referring physicians and bariatric specialists need to take a greater role in personalizing vitamin D
supplementation regimens in these patients.
Even most referring physicians aren't
aware of the importance of early vitamin D intervention or may not be
addressing the issue in the most effective manner. Even with the
latest medical research, doctors specializing in bariatric surgery do
not yet know the best vitamin D supplementation regimen for these
patients. As a result, the referring physicians and bariatric
specialists should be working together to closely monitor and tailor
an individualized supplement regimen for each patient.
The best method of treating vitamin D
malnutrition pre- and post-bariatric surgery is to deliver a higher
daily dose of vitamin D and then adjust to the appropriate blood
25(OH)D readings, which will require personalized medicine and
treatment from both referring physicians and bariatric specialists.
Personalized vitamin D supplementation will prevent both under- and
overtreatment in bariatric surgery patients and is likely also
important for many other patient populations who are at risk for
vitamin D deficiency, including people who have obesity or in those
who are overweight.
Until recently, vitamin D deficiency
after bariatric surgery was thought to be due to side effects of the
procedure, i.e., poor absorption of fat-soluble nutrients. It has
been determined now that vitamin D deficiency stems of pre-surgery
malnutrition with up to 98 percent of bariatric surgery candidates
having vitamin D deficiency. This malnutrition persists after
surgery despite supplementation and weight loss, which theoretically
releases vitamin D stored in the fat.
The primary concern over vitamin D
deficiency is that the risk of deficiency is even greater after
bariatric surgery when these patients may be less able to absorb
vitamin D, and, thus, treatment before surgery may be more effective.
Improving vitamin D status before surgery may also improve healing
and shorten the length of stay in the hospital following bariatric
surgery.
What is an optimized vitamin D level in
a patient before or following bariatric surgery? According to the
2013 American Society for Metabolic and Bariatric Surgery guidelines,
physicians should bring blood concentrations to greater than 30 ng/mL
of 25-hydroxyvitamin D, the circulating form of vitamin D. The
society recommends achieving these readings by delivering the
standard daily dose of at least 3,000 IU, test the patient's blood,
adjust the dose, test again and repeat until the patient's vitamin D
readings are optimized. A physician may consider giving high doses
of vitamin D -- 50,000 IU one to three times weekly or even daily --
if necessary for patients following surgery. The recommendations
from the society sound like a ringing endorsement for personalized
medicine.
A key consideration in vitamin D
supplementation that physicians need to be aware of is the form of
vitamin D given. Vitamin D3 is made in the skin during sun exposure
and is found in over-the-counter supplements, whereas vitamin D2 is
uncommon in the diet and found in high-dose prescription vitamin D
supplements. In a meta-analysis of 57 studies, patients given vitamin
D3 had an 8.08-ng/mL larger improvement in 25(OH)D readings over the
same dose of vitamin D2 -- meaning vitamin D3 proved more effective.
Despite this, many doctors inadvertently prescribe vitamin D2 to
their bariatric surgery patients. Many doctors do not realize that
writing a prescription for vitamin D will likely yield vitamin D2,
and many also do not know the difference in effectiveness between
these two forms. I recently showed that 87% of our bariatric surgery
candidates prescribed high-dose vitamin D were given vitamin D2,
despite that many patients only get a short window for preoperative
treatment.
As for the appropriate dosing regimen,
of 25 separate studies testing different regimens, none of these
studies reported consistently optimized vitamin D readings in
patients. These studies ranged from a daily multivitamin to high
doses of vitamin D (50,000 IU monthly or weekly) and various
combinations of daily and high doses. These findings from my recent
review echo the society's recommendations, yet no studies giving
dosages up to 5,000 IU daily reached optimized vitamin D readings
universally. However, some patients did reach blood concentrations
over the recommended 30 ng/mL. Would the best course of treatment
really be to increase the standard dose for all, or should we only
increase the dosage for those patients who are still below the
recommended concentration?
With this discussion, I also have to
wonder if the other vitamins and minerals are monitored and kept at
the correct levels as I have seen other studies reporting
deficiencies in other vitamins as well.
No comments:
Post a Comment