http://www.nlm.nih/gov/medlineplus/druginfo/natural/
patient-vitamina.html>
Office of Dietary Supplements. ’’Dietary Supplements Fact
Sheet: Vitamin A and Carotenoids.‘‘ National Institutes
of Health, April 23, 2006.<http://dietary-supplements.
info.nih.gov/factsheets/Vitamin_A.asp>
Stenson, Jacqueline. ‘‘A Vitamin A Day May Do More
Harm Than Good.’’ MSNBC.com, January 19, 2007.
<http://www.msnbc.com/id/16655168>
Thakore, Jigna. ‘‘Vitamin A Deficiency.’’ emedicine.com,
May 12, 2006.<http://www.emedicine.com/med/
topic2381.htm>
UNICEF. ‘‘Vitamin A Deficiency.’’ United Nations, May
2006.<http://www.childinfo.org/areas/vitamina>Tish Davidson, A.M.Vitamin B 5 seePantothenic acid
Vitamin B 6
Definition
Vitamin B 6 is a water-soluble organic compound
that the body needs to remain healthy. Humans can-
not make vitamin B 6 , so they must get it from foods in
their diet. Vitamin B 6 is sometimes called pyridoxine.Purpose
Vitamin B 6 has a broad range activities and is
necessary for the correct functioning of many systems
in the body. It plays a role in the transmission of nerve
impulses, formation and functioning of red blood
cells, formation of new cells skin and other cells, and
conversion of storedcarbohydratesinto energy. It
aids in the production of DNA (genetic material)
and, along with vitamin B 12 and folic acid (vitamin
B 9 ), it helps regulate the levels of an amino acid
(homocysteine) in the blood thought to be linked to
heart disease.Description
Vitamin B 6 is not a single compound. It has three
different forms: pyrodoxine, pyridoxal, pyridoxamine,
and three derivatives of these forms. All forms of
vitamin B 6 are converted in the body into the same
active molecule, pyridoxal 5’-phosphate (PLP). Vita-
min B 6 is a water-soluble vitamin. Unlike the fat-solu-
blevitaminsA, D, E, and K, it is not stored in the body
but is excreted in urine.Normal vitamin B 6 requirements
The United States Institute of Medicine (IOM) of
the National Academy of Sciences has developed val-
ues calledDietary Reference Intakes(DRIs) for vita-
mins andminerals. The DRIs consist of three sets of
numbers. The Recommended Dietary Allowance
(RDA) defines the average daily amount of the
nutrient needed to meet the health needs of 97–98%
of the population. The Adequate Intake (AI) is an
estimate set when there is not enough information to
determine an RDA. The Tolerable Upper Intake Level
(UL) is the average maximum amount that can be
taken daily without risking negative side effects. The
DRIs are calculated for children, adult men, adult
women, pregnant women, andbreastfeedingwomen.
The IOM has not set RDA or UL values for
vitamin B 6 in children under one year old because of
incomplete scientific information. Instead, it has setVitamin B 6Recommended
Dietary Allowance Tolerable Upper
Age (mg) Intake Level (mg)
Children 0–6 mos. 0.1 (AI) Not established
Children 7–12 mos. 0.3 Not established
Children 1–3 yrs. 0.5 30
Children 4–8 yrs. 0.6 40
Children 9–13 yrs. 1.0 60
Boys 14–18 yrs. 1.3 80
Girls 14–18 yrs. 1.2 80
Adults 19–50 yrs. 1.3 100
Men 51 yrs. 1.7 100
Women 51 yrs. 1.5 100
Pregnant women 1.9 100
Breastfeeding women 2.0 100
Food Vitamin B 6 (mg)
Cereal, 100% fortified, ¾ cup 2.0
Potato, baked, med. with skin 0.70
Banana, 1 med. 0.68
Chicken or turkey breast, roasted, 4 oz. 0.64
Cod, baked or broiled, 4 oz. 0.52
Salmon, baked or broiled, 4 oz. 0.52
Cereal, 25% fortified, ¾ cup 0.50
Beef tenderloin, lean, 4 oz. 0.49
Halibut, baked or broiled, 4 oz. 0.45
Pork loin, lean, 3 oz. 0.42
Spinach, fresh, cooked, ½ cup 0.22
Watermelon, 1 cup 0.22
Carrots, raw, 1 cup 0.18
Tuna, canned, 3 oz. 0.18
Green peas, ½ cup 0.17
Peanut butter, smooth, 2 tbsp. 0.15
Spinach, frozen, cooked, ½ cup 0.14
AI Adequate Intake
mg milligram(Illustration by GGS Information Services/Thomson Gale.)Vitamin B
6