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What
is it?
Niacin is a water-soluble
vitamin, and was formely known as vitamin B-3. The term
niacin refers to the general name for nicotinic acid and nicotinamide,
which both form part of the coenzymes, nicotinamide adenine
dinucleotide (NAD) and nicotinamide adenine dinucleotide phospate
(NADP).
Functions
- what does it do?
Niacin forms
part of coenzymes that are essential in the reactions involved
in the release of energy from carbohydrates, fats and proteins.
Requirements
- How much do we need?
|
|
| |
Recommended
Dietary Allowance*
(mg of Niacin Equivalents (NE#)/day) |
| Life-Stage
(years) |
Males |
Females |
| 0
- 0.5 (0 - 6 months) |
2a |
2a |
| 0.5
- 1 (7 - 12 months) |
4a |
4a |
| 1
- 3 |
6 |
6 |
| 4
- 8 |
8 |
8 |
| 9
- 13 |
12 |
12 |
| 14
- 18 |
16 |
14 |
| Ages
19+ |
16 |
14 |
| Life-Stage
(years) |
Pregnancy |
Lactation |
| 18
and younger |
18 |
17 |
| 19
- 30 |
18 |
17 |
| Ages
31+ |
18 |
17 |
| #1
mg NE = 60 mg of tryptophanø (amino acid)
= 1 mg niacin |
|
øThe
amino acid, tryptophan, can be converted to niacin in
the body |
*The
Recommended Dietary Allowance (RDA) is the average daily
dietary intake level that is sufficient to meet the nutrient
requirements of nearly all (97-98%) healthy individuals
in each life-stage and gender group.
aAdequate
Intakes (AI) are used as no RDA is established. The
AI is a recommended daily intake level based on observed
or experimentally determined approximations of nutrient
intake by a group of healthy people who are assumed to be
maintaining an adequate nutritional state. |
|
Sources
- Where is it found?
|
|
| Nutrient
Density |
| High |
Medium |
Low |
|
| Niacin |
|
Tryptophan |
| Rich
sources Lean
meats, Poultry, Fish, Peanuts, Peanut butter, Organ
meats, Brewer's yeast |
Rich
sources Lean
meats, Poultry, Fish, Peanuts, Milk, Eggs
|
| Other
sources Beans,
Peas, Other legumes, Most nuts, Whole grains or
Enriched cereals |
Other
sources Beans,
Peas, Other legumes, Most nuts, Whole grains or
Enriched cereals |
| Poor
sources Milk,
Eggs, Vegetables, Fruits |
|
|
|
Deficiency
- When you have too little
Symptoms of niacin
deficiency in the early stages include muscular weakness, anorexia
(loss of appetite), indigestion, and skin eruptions.
Pellagra.
The late stage of severe niacin deficiency is known as pellagra.
The most common symptoms involve the skin, digestive system,
and the nervous system. In the skin, a thick, scaly, darkly
pigmented rash develops, similar to a sunburned outbreak, in
areas exposed to sunlight, such as hands, forearm, neck and
legs. Symptoms related to the digestive system include a bright
red and swollen tongue, vomiting, and diarrhoea. The central
nervous system is also affected and symptoms include headache,
apathy, fatigue, depression, disorientation, and memory loss.
If untreated, pellagra is ultimately fatal.
Toxicity
- When you have too much
Niacin from foods
is not known to cause adverse effects. Niacin can become
toxic at 100 mg or more of the nicotinic acid form. Effects
include headache, itching, flushing and gastrointestinal
disturbances such as nausea and vomiting.
|
Upper
Limit+
(mg of Niacin Equivalents#/day)
|
| Life-Stage
(years) |
Males |
Females |
| 0
- 0.5 (0 - 6 months) |
ND |
ND |
| 0.5
- 1 (7 - 12 months) |
ND |
ND |
| 1
- 3 |
10 |
10 |
| 4
- 8 |
15 |
15 |
| 9
- 13 |
20 |
20 |
| 14
- 18 |
30 |
30 |
| Ages
19+ |
35 |
35 |
| Life-Stage
(years) |
Pregnancy |
Lactation |
| 18
and younger |
30 |
30 |
| 19
- 30 |
35 |
35 |
| Ages
31+ |
35 |
35 |
|
#1
mg Niacin Equivalents (NE) = 60 mg of tryptophan (amino
acid) = 1 mg niacin |
| |
|
|
| +Upper
Limits (UL) = The maximum level of daily nutrient intake
that is likely to pose no risk of adverse effects. Unless
otherwise specified, the UL represents total intake from
food, water, and supplements.
ND = Not
determinable due to lack of data of adverse effects in
this age group and concern with regard to lack of ability
to handle excess amounts. Source of intake should be from
food only to prevent high levels of intake. |
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