23
Micronutrient Deficiency Replacement After
Bariatric Surgery: Vitamins
Vitamin/
Mineral Assessment
Replacement of Deficiency and
Maintenance
Vitamin A Retinol • If def iciency and corneal keratinization,
ulceration or necrosis: 50,000–100,000
IU IM for 3 days, followed by 50,000 IU
per day IM for 2 weeks
• If def iciency and no corneal changes:
10,000–25,000 IU orally per day until
clinical improvement (may take at least
1–2 weeks)
• Maintenance dose: 5000–10,000 IU
orally per day (lower dose without
clinical malabsorption and higher dose
with clinical malabsorption), as found in
many bariatric multivitamins
• With biliopancreatic diversion/duodenal
switch specif ically, consider 10,000 IU
orally per day
Vitamin B1
(Thiamine)
Thiamine • With potential thiamine def iciency,
thiamine is best given before glucose
to avoid iatrogenic neurologic
complications, and magnesium (a
thiamine cofactor) def iciency might
also best be corrected as well
• With def iciency (Wernicke's
encephalopathy), thiamine 100 mg
orally 3 times per day; if possible
malabsorption, hyperemesis, or
unable to give orally, then thiamine
500mg IV twice a day for 5 days, then
250 mg IV until symptoms resolve,
and then 100 mg orally per day for
patients with persistent risk factors for
thiamine def iciency such as chronic
malnutrition or malabsorption (may
require additional supplement beyond
a bariatric multivitamin)
• Maintenance oral: vitamin B1 of at least
12 mg orally per day, as often found in
many bariatric multivitamins
• Thiamine can also be given
intramuscularly, starting with 250 mg
per day for 5 days, and then 100–250 mg
monthly
(cont'd)
