Vitamin A

Studies of vitamin and mineral deficiencies occurring after
bariatric surgery are numerous. However, the next question to ask is “how
much is too much?” In the renal dialysis population, toxicity of vitamin A
is a concern as they may have levels higher than people without renal
disease even without supplementation.

A study published in 2010 looked at vitamin and mineral levels in gastric
sleeve patients. They noted multiple vitamin and mineral deficiencies and
hypervitaminosis A was found in 26 (48%) of their 60 study participants. In
addition, thiamine and vitamin B6 levels were elevated in about 30 percent
of participants. The levels of B vitamins were not considered to be
harmful.

High levels of preformed vitamin A (retinol) can lead to problems, such as
ataxia, alopecia, dry skin, and liver problems. They can affect bone health
by causing resorption of bone. In the study by Aarts EO et al,a
multiple vitamin that included the RDA for vitamin A was recommended three
times per day. A multiple vitamin provided three times a day is in excess of
recommended supplementation guidelines published by the ASMBS.This
study does not state how much of the vitamin A was preformed (retinol)
versus betacarotene. Serum levels of vitamin A did not did not exceed 4
µmol/L after one year of supplementation.