Chemistry Reference
In-Depth Information
Table 13.3.
Recommended daily uptake of niacin
Niacin (mg equivalent day
-1
)1mg
niacin equivalent
¼
60 mg tryptophan
Age
Male
Female
Sucklings
<
4 months
2 (estimated)
Sucklings 4-12 months
5
Children 1-4 years
7
Children 4-7 years
10
Children 7-10 years
12
Children 10-13 years
15
13
Children 13-15 years
18
15
Adults 15-25 years
17
13
Adults 25-51 years
16
13
Adults 51-65 years
15
13
Adults
>
65 years
13
13
Pregnant (
>
4 month)
15
Breast feeding
17
From DGE (2007)
synthesized from tryptophan when the latter is sufficiently available. There-
fore, the niacin content of the diet is often expressed as niacin equivalents, i.e. 1
NE
¼
1mgniacin
¼
60 mg tryptophan. The tryptophan content of some
selected foods as a percentage of total protein is as follows: eggs (1.5%), milk
(1.4%), meat products (
>
1.1%), cereals, fruits, vegetables (
1%) and maize
(
0.6%). A ''normal, mixed diet'' in industrial countries includes about 13 mg
NE day
-1
, thus meeting more than the requirements (see Table 13.3). Milk, as
an example, is regarded as a good pellagra-preventing food (see below), not
because of its relatively low, niacin concentration but because of its high
concentration of tryptophan (see above). Other good sources for niacin are
shown in Table 13.5, concerning milk and dairy products in Table 13.6. Side
effects due to niacin uptake have been observed only after excess uptake over at
least months (Nohr, 2009b).
The main disease resulting from niacin deficiency is called pellagra
(Pellagrosis; maidism; mal de la rosa, Saint Ignatius Itch, erythema endemi-
cum; Jolliffe syndrome; Hegyi, 2004; Kumaravel, 2006; Nohr, 2009a). It is
characterized by the three Ds: dermatitis, diarrhoea, dementia. The name
''pellagra'' is derived from ''pelle agra''
¼
''rough skin'', i.e. the prominent
appearance is a rough skin in light-exposed areas with a symmetric appear-
ance with a distinct border to normal skin (glove-like appearance of the
hands). Disorders of the gastrointestinal tract (GIT) can include nausea,
abdominal pain, increased salivation, soreness of the mouth, inflammation
of the mucosa and diarrhoea. Early neurologic disorders are depression,
