nutrient needed to meet the health needs of 9,798 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 with-
out risking negative side effects. The DRIs are calcu-
lated for children, adult men, adult women, pregnant
women, andbreastfeedingwomen.
The IOM has not set RDAs for magnesium in
children under one year old because of incomplete
scientific information. Instead, it has set AI levels for
this age group. The RDAs for magnesium are the
amount that has been determined to prevent defi-
ciency. However, based on recent findings about the
relationship between magnesium, diabetes, and cardi-
ovascular disease, there is some debate over whether
this represents the optimum amount for health. RDAs
and ULs for magnesium are measured in milligrams
(mg). There are no ULs for magnesium that is
obtained from food and water. All magnesium ULs
apply todietary supplementsonly.
The following list gives the daily RDAs and IAs
and ULs for magnesium for healthy individuals as
established by the IOM.
children birth–6 months: AI 30 mg; UL not estab-
lished; All magnesium should come from breast milk,
fortified formula, or food.
children 7–12 months: AI 75 mg; UL not established;
All magnesium should come from breast milk, for-
tified formula, or food.
children 1–3 years: RDA 80 mg; UL 65 mg
children 4–8 years: RDA 130 mg; UL 110 mg
children 9–13 years: RDA 240 mg; UL 350 mg
boys 14–18 years: RDA 410 mg; UL 350 mg
girls 14–18 years: RDA 360 mg; UL 350 mg
men 19–30 years: RDA 400 mg; UL 350 mg
women 19–30 years: RDA 310 mg; UL 350 mg
men age 31 and older: RDA 420 mg; UL 350 mg
women age 31 and older: RDA 320 mg; UL 350 mg
pregnant women 18 years and younger: RDA
400 mg; UL 350 mg
pregnantwomen19–30years:RDA350mg;UL350mg
pregnant women 31 years and older: RDA 360 mg;
UL 350 mg
breastfeeding women 18 years and younger: RDA
360 mg; UL 350 mg
breastfeeding women 19–30 years: RDA 310 mg; UL
350 mg
breastfeeding women 31 years and older: RDA 320
mg; UL 350 mg
Sources of magnesium
Chlorophyll, the pigment that makes plants green,
contains magnesium. Good natural sources of magne-
sium include dark green vegetables such as spinach
and Swiss chard. Other vegetables high in magnesium
are lima beans, black-eyed peas, almonds, cashew
nuts, and peanuts. Whole grains contain a lot of mag-
nesium, but processing removes most of it. Therefore
brown rice is a good source of magnesium, but white
rice is not. Whole wheat flour has more magnesium
than white flour, and wheat bran and oat bran have
more than either type of flour. Some water that is high
in minerals (hard water) has a significant amount of
magnesium; the amount varies widely depending on
location. Magnesium is also found in many multivita-
mins and is available as a single-ingredient supple-
ment. The amount of magnesium available to the
body from dietary supplements varies depending on
the molecule in which magnesium is found. Common
forms of magnesium in dietary supplements include
magn! esium oxide, magnesium gluconate, magnesium
citrate, and magnesium aspartate. Some antacids con-
tain a significant amount of magnesium hydroxide.
The best way to get an adequate amount of magne-
sium is to eat a healthy diet high in green vegetables
and whole grains.
The following list gives the approximate magne-
sium content for some common foods:
100% bran cereal, 1/2 cup: 129 mg
oat bran, 1/2 cup dry: 96 mg
shredded wheat, 2 biscuits: 54 mg
halibut, cooked 3 ounces: 90 mg
almonds, roasted, 1 ounce: 80 mg
cashew nuts, roasted, 1 ounce:75 mg
peanuts, roasted, 1 ounce: 50 mg
spinach, cooked, 1/2 cup: 75 mg
Swiss chard, cooked, 1/2 cup: 75 mg
lima beans, cooked, 1/2 cup: 63 mg
black-eyed peas, cooked, 1/2 cup: 43 mg
pinto beans, cooked, 1/2 cup: 35 mg
brown rice, cooked, 1/2 cup: 40 mgMagnesium excess and deficiency
Magnesium excess is called hypermagnesemia.
This condition is rare. It occurs most often in people
with severe kidney disease (end-stage renal failure),
when the kidney can no longer remove magnesium
ions from the blood. Another common cause is
human error in calculating the amount of intravenous
(IV) fluids containing magnesium to give to seriouslyMagnesium