with Vitamin A (Retinol)|
A multi-center, randomized, prospective study involving 60 patients with
chronic gastric ulcers evaluated the effects of vitamin A supplementation on
ulcer healing (Patty et al. 1983). Patients were divided into three groups and
treated for four weeks with antacids only, antacids plus vitamin A (50,000 IU po
tid), or antacids, vitamin A, and cyproheptadine (4 mg po tid). Endoscopic
analysis revealed that gastric ulcers were completely healed in 15 out of 40
patients who received vitamin A. The reduction in ulcer size was greater in the
group receiving vitamin A plus antacids after both two and four weeks of use.
This study suggests that the combination of vitamin A and antacids may be more
effective than antacids alone to heal
HMG-CoA reductase inhibitors may increase blood vitamin A levels (Muggeo et
In one study involving 17 patients with severe cystic acne, subjects received
isotretinoin (0.5mg/kg/day) for 3 months; eight patients continued to receive
isotretinoin (0.75 mg/kg/day) for another 3 months (Rollman and Vahlquist 1986).
After 3 months of therapy, epidermal retinol content increased by 53%, while
dehydroretinol decreased by 79%. These findings were corroborated in another
study with 22 subjects (Vahlquist et al. 1990). Administration of isotretinoin
(1 mg/kg/day) for four months led to a marked increase in retinol and a decrease
in dehydroretinol content in the skin. Individuals should avoid consuming high
doses of vitamin A while taking tretinoin unless prescribed by a physician.
In a double-blind study in five healthy males, study participants consumed a
standard meal containing vitamin A (300,000 IU) followed by either neomycin
sulfate (2 g) or placebo (Barrowman et al. 1972). The rise in plasma vitamin A
levels was significantly less after neomycin treatment in all study subjects.
Neomycin interferes with the absorption of vitamin A when delivered in a very
large bolus dose. The significance of this interaction on daily supplementation
of vitamin A is
Omeprazole significantly suppressed the blood response to beta-carotene (120
mg po) in healthy subjects (Tang et al. 1996). Serum beta-carotene levels were
significantly greater during the low gastric pH phase of the study compared to
the high gastric pH phase. It is not known if omeprazole or lansoprazole
adversely affect carotenoid absorption from
Oral contraceptives increase the levels of vitamin A in women (Tyrer 1984).
Barrowman J, Broomhall J, Cannon A, et al. Impairment of vitamin A absorption
by neomycin. Clin Sci. 1972;42:17P.
Muggeo M, Zenti MG, Travia D, et al. 1995. Serum retinol levels throughout 2
years of cholesterol-lowering therapy. Metab. 1995;44(3):398-403.
Patty I, Benedek S, Deak G, et al. Cytoprotective effect of vitamin A and its
clinical importance in the treatment of patients with chronic gastric ulcer.
Int J Tissue React. 1983;5:301-307.
Rollman O, Vahlquist A. Oral isotretinoin (13-cis-retinoic acid) therapy in
severe acne: drug and vitamin A concentrations in serum and skin. J Invest
Tang G, Serfaty-Lacrosniere C, Camilo ME, Russell RM. Gastric acidity
influences the blood response to a beta-carotene dose in humans. Am J Clin
Tyrer LB. Nutrition and the pill. J Reprod Med. 1984;29(7
Vahlquist A, Rollmann O, Hollan D, Cunliffe, W. Isotretinoin treatment of
severe acne affects the endogenous concentration of vitamin A in sebaceous
glands. J Invest Dermatol.
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