Which statement accurately describes vitamin deficiencies?
a). The two nutrients most often lacking in the diet of a vegan are vitamin B6 and folic acid.
b). Vitamin imbalances occur frequently in the United States because of excessive fat intake.
c). Surgery on the GI tract may contribute to vitamin deficiencies because of impaired absorption.
d). Vitamin deficiencies in adults most commonly are clinically manifested by disorders of the skin.