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The body requires different amounts of each vitamin and mineral because each has a different function. People have different requirements according to their age, sex, level of activity and state of health.
Eggs contain some of most of the recognised vitamins and minerals that help to maintain essential bodily functions. There is also evidence that other substances found in eggs but are not classified as nutrients - the carotenoids lutein and zeaxanthin - might be involved in the prevention of cataracts and age-related macular degeneration (AMD), a major cause of blindness in elderly people, although this is the subject of continuing debate.1,2
Eggs are also rich in choline, an essential component of all cells. Recent research suggests that choline may have a role in normal development of memory.3,4 It is not regarded as an essential nutrient in the UK, but on the basis of emerging evidence, the US Institute of Medicine has set Adequate Intake (AI) recommendations for choline, with the caveat that it may not be a dietary essential at all stage in the lifecycle.5,6
The three tables below indicate the more recognised nutrients found in eggs and their benefits.
Fat Soluble Vitamins
| Vitamins |
Main Functions |
Sources |
Deficiency |
Excess |
| A |
Essential for vision in dim light; necessary for maintenance of mucous membranes; skin and growth. |
As retinol in milk, fortified margarine, butter, cheese, egg yolk, liver and fatty fish. As carotenes in milk, carrots, tomatoes, dark green vegetables. |
Reduced night vision; loss of sight through gradual damage to the cornea. Lowered resistance to infection. |
Vitamin A is stored in the liver and toxicity can occur. |
| D |
Promotes calcium and phosphate absorption from food and is thus essential for bones and teeth. |
Sunshine, fortified margarine, oily fish, egg yolk, fortified breakfast cereals. |
Failure of bones to grow and calcify leading to rickets in children and osteomalacia in adults. |
Vitamin D can be toxic. |
| E |
Protects cell membranes from damage by oxidation. |
Eggs, vegetable oils, nuts, vegetables and cereals. |
Deficiency may occur in premature infants or due to malabsorption. |
Not known. |
Water Soluble Vitamins
| Vitamins |
Main Functions |
Sources |
Deficiency |
Excess |
| Thiamin (B1) |
Involved in the release of energy from carbohydrate. It is important for the brain and nerves, which use glucose for their energy needs. |
Cereals, nuts and pulses are rich sources. Green vegetables, pork, fruits and fortified cereals contain thiamin. |
Deficiency leads to beriberi. Alcoholics sometimes develop deficiency. |
The body excretes excess thiamin. |
| Riboflavin (B2) |
Involved in energy release, especially from fat and protein. |
Rich sources are liver, milk, cheese, yoghurt, eggs, green vegetables and yeast extract, and fortified cereals. |
Deficiency includes changes to the mucous membrane and skin around the mouth and nose. |
The body excretes excess riboflavin. No known adverse effect. |
| Vitamin B6 (Pyridoxine) |
Involved in the metabolism of protein. |
Found in a variety of foods: beef, fish and poultry are rich sources. |
Deficiency may occur as a complication of disease and drug effects. |
High intakes (from vitamin pills) may be harmful. |
| B12 |
Is necessary for the proper formation of blood cells and nerve fibres. |
Rich sources are offal, meat and eggs. Dairy products such as milk also contain B12. Almost no plant foods contain B12. Fortified breakfast cereals are a useful source. |
Deficiency leads to pernicious anaemia. |
No toxic effects known. |
| Folate |
Involved in the formation of blood cells. Reduces the risk of Neural tube defects in babies. |
Liver, orange juice, dark green vegetables are rich sources. Nuts, wholemeal bread, and fortified breakfast cereals and eggs are also sources. |
Deficiency leads to megaloblastic anaemia. |
No toxic effects known. |
Mineral
| Mineral |
Main Functions |
Sources |
Deficiency |
Excess |
| Calcium |
Calcium is the main constituent of hydroxyapatite, the principal mineral in bones and teeth. An adequate calcium intake is vital to health, particularly in times of growth, e.g. childhood, adolescence, pregnancy, and also during lactation. |
In milk and dairy products calcium is readily available, but it is usually less available from plant foods. Calcium is sometimes bound by phytates (found in wholegrain cereals and pulses) and oxalates (found in spinach and rhubarb) that reduce its availability. |
Deficiency of calcium in bones can result from an inadequate supply of vitamin D, which is essential for its absorption. This condition is known as rickets in children and osteomalacia in adults. |
No known toxic effects. |
| Phosphorus |
80% of the phosphorus in the body is present as calcium salts in the skeleton. |
Phosphorus is present in all plant and animal cells. |
|
Affects calcium balance. |
| Iron |
Iron is required for the formation of haemoglobin in red blood cells, which transport oxygen around the body. |
Iron is found in plant and animal sources. Bread and many breakfast cereals are fortified with iron in the UK. Iron is particularly well-absorbed from haem sources such as red meat. The absorption of iron from non-haem sources such as eggs is enhanced by the presence of vitamin C. |
A lack of iron leads to lower iron stores in the body and eventually to iron deficiency anaemia. Low iron status is associated with poor physical and mental performance. |
No known toxic effects. |
| Iodine |
Iodine is used to make thyroid hormones, which control many metabolic activities. |
Seafood, salt and bread, dairy products and eggs. |
Lethargy and swelling of the thyroid gland in the neck to form a goitre. Nowadays this is rare in the UK. Infants born of severely iodine deficient mothers may be mentally retarded (cretinism). |
No known toxic effects. |
| Selenium |
As an antioxidant it protects cell membranes against oxidation. |
Cereals, meat, fish, offal, cheese and eggs. Dietary selenium levels in the UK have declined in recent years, largely due to shifting wheat supplies from North American to European sources. |
Keshan disease (type of heart disease). |
Excess selenium is toxic. |
| Zinc |
Essential for growth, and sexual maturation. Involved in enzyme activity and taste perception. |
Milk, cheese, meat, eggs and fish, wholegrain cereals and pulses. |
Dietary deficiency is rare; may cause delayed puberty and retarded growth. |
Interferes with copper metabolism. |
References:
1. Suzen M. Moeller, Paul F. Jacques, Jeffrey B. Blumberg, The Potential of Dietary Xanthophylls in Cataract and Age-Related Macular Degeneration, Journal of the American College of Nutrition, 19, 522S, 2000
2. Chong, E W-T, Wong TY, Kreis AJ, Simpson JA, Guymer RH, Dietary antioxidants and primary prevention of age related macular degeneration: systematic review and meta-analysis. British Medical Journal, 335, 755, 2007
3. Steven H.Zeisel, Choline: Needed for Normal Development of Memory, Journal of the American College of Nutrition, 19, 528S, 2000
4. Steven H Zeisel, Nutritional importance of choline for brain development. Journal of the American College of Nutrition, 23, 62S-626S, 2004
5. Dietary Reference Intakes, Institute of Medicine of the National Academies, National Academies Press, Washington, DC, 2006.
6. Dietary Reference Intakes Research Synthesis: Workshop Summary (2006) http://www.nap.edu/openbook.php?record_id=11767&page=42
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The body requires different amounts of each vitamin and mineral because each of them has a different function. People have different requirements according to their age, sex, level of activity and state of health. The Department of Health has drawn up Dietary Reference Values (DRVs) for all nutrients for all different groups of healthy people in the UK1. The Reference Nutrient Intake (RNI) level meets the needs of practically all of the population.
The tables below indicate the RNI values for the vitamins and minerals found in eggs and also the percentage of each vitamin and mineral found in a medium sized egg (average weight 58g, assuming edible portion 89%).
Vitamins
| Age |
Vitamin A
mg/d |
% in an egg |
Vitamin D
mg/d |
% in an egg |
Thiamin
mg/d |
% in an egg |
Niacin
mg/d |
% in an egg |
Riboflavin
mg/d |
% in an egg |
Vitamin B6
mg/d |
% in an egg |
Vitamin B12
mg/d |
% in an egg |
Folate
m g/d |
% in an egg |
| 7-9 months |
350 |
28% |
7 |
13% |
0.2 |
25% |
4 |
49% |
0.4 |
60% |
0.3 |
20% |
0.4 |
325% |
50 |
52% |
| 10-12 months |
350 |
28% |
7 |
13% |
0.3 |
17% |
5 |
39% |
0.4 |
60% |
0.4 |
15% |
0.4 |
325% |
50 |
52% |
| 1-3 years |
400 |
25% |
7 |
13% |
0.5 |
10% |
8 |
24% |
0.6 |
40% |
0.7 |
9% |
0.5 |
260% |
70 |
37% |
| 4-6 years |
500 |
20% |
- |
- |
0.7 |
7% |
11 |
17% |
0.8 |
30% |
0.9 |
7% |
0.8 |
163% |
100 |
26% |
| 7-10 years |
500 |
20% |
- |
- |
0.7 |
7% |
12 |
16% |
1.0 |
24% |
1.0 |
6% |
1.0 |
130% |
150 |
17% |
| Males |
| 11-14 years |
600 |
16% |
- |
- |
0.9 |
6% |
15 |
12% |
1.2 |
20% |
1.2 |
5% |
1.2 |
108% |
200 |
13% |
| 15-18 years |
700 |
14% |
- |
- |
1.1 |
5% |
18 |
10% |
1.3 |
18% |
1.5 |
4% |
1.5 |
87% |
200 |
13% |
| 19-50 years |
700 |
14% |
- |
- |
1.0 |
5% |
17 |
11% |
1.3 |
18% |
1.4 |
4% |
1.5 |
87% |
200 |
13% |
| 50+ years |
700 |
14% |
** |
- |
0.9 |
6% |
16 |
12% |
1.3 |
18% |
1.4 |
4% |
1.5 |
87% |
200 |
13% |
| Females |
| 11-14 years |
600 |
16% |
- |
- |
0.7 |
7% |
12 |
16% |
1.1 |
22% |
1.0 |
6% |
1.2 |
108% |
200 |
13% |
| 15-18 years |
600 |
16% |
- |
- |
0.8 |
6% |
14 |
14% |
1.1 |
22% |
1.2 |
5% |
1.5 |
87% |
200 |
13% |
| 19-50 years |
600 |
16% |
- |
- |
0.8 |
6% |
13 |
15% |
1.1 |
22% |
1.2 |
5% |
1.5 |
87% |
200 |
13% |
| 50+ years |
600 |
16% |
** |
- |
0.8 |
6% |
12 |
16% |
1.1 |
22% |
1.2 |
5% |
1.5 |
87% |
200 |
13% |
| |
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| Pregnancy |
+100 |
14% |
10 |
9% |
+0.1*** |
6% |
* |
|
+0.3 |
17% |
* |
|
* |
- |
+100 |
9% |
| Lactation |
| 0-4 months |
+350 |
10% |
10 |
9% |
+0.2 |
5% |
+2 |
13% |
+0.5 |
15% |
* |
|
+0.5 |
65% |
+60 |
10% |
| 4+ months |
+350 |
10% |
10 |
9% |
+0.2 |
5% |
+2 |
13% |
+0.5 |
15% |
* |
|
+0.5 |
65% |
+60 |
10% |
*No increment **After age 65 the RNI is 10 m g/d for men and women ***For last trimester only
Reference:
1 Department of Health (1991) Dietary Reference Values for Food Energy and Nutrients for the United Kingdom. Report on Health and Social Subjects no.41. HMSO, London.
Minerals
| Age |
Calcium
mg/d |
% in an egg |
Phosphorus
mg/d |
% in an egg |
Potassium
mg/d |
% in an egg |
Magnesium
mg/d |
% in an egg |
Zinc
mg/d |
% in an egg |
Iron
mg/d |
% in an egg |
| 7-9 months |
525 |
6% |
400 |
26% |
700 |
10% |
75 |
8% |
5.0 |
14% |
7.8 |
13% |
| 10-12 months |
525 |
6% |
400 |
26% |
700 |
10% |
80 |
8% |
5.0 |
14% |
7.8 |
13% |
| 1-3 years |
350 |
8% |
270 |
38% |
800 |
8% |
85 |
7% |
5.0 |
14% |
6.9 |
14% |
| 4-6 years |
450 |
6% |
350 |
29% |
1100 |
6% |
120 |
5% |
6.5 |
11% |
6.1 |
16% |
| 7-10 years |
550 |
5% |
450 |
23% |
2000 |
3% |
200 |
3% |
7.0 |
10% |
8.7 |
11% |
| Males |
| 11-14 years |
1000 |
3% |
775 |
13% |
3500 |
2% |
280 |
2% |
9.0 |
8% |
11.3 |
9% |
| 15-18 years |
1000 |
3% |
775 |
13% |
3500 |
2% |
300 |
2% |
9.5 |
7% |
11.3 |
9% |
| 19-50 years |
700 |
4% |
550 |
19% |
3500 |
2% |
300 |
2% |
9.5 |
7% |
8.7 |
11% |
| 50+ years |
700 |
4% |
550 |
19% |
3500 |
2% |
300 |
2% |
9.5 |
7% |
8.7 |
11% |
| Females |
| 11-14 years |
800 |
4% |
625 |
17% |
3500 |
2% |
280 |
2% |
9.0 |
8% |
14.8 |
7% |
| 15-18 years |
800 |
4% |
625 |
17% |
3500 |
22% |
300 |
2% |
7.0 |
10% |
14.8 |
7% |
| 19-50 years |
700 |
4% |
550 |
19% |
3500 |
2% |
300 |
2% |
7.0 |
10% |
14.8 |
7% |
| 50+ years |
700 |
4% |
550 |
19% |
3500 |
10% |
300 |
2% |
7.0 |
10% |
8.7 |
11% |
| |
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| Pregnancy |
* |
|
* |
|
* |
|
* |
|
* |
|
* |
|
| Lactation |
|
|
|
|
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|
|
| 0-4 months |
+550 |
2% |
440 |
10% |
* |
|
+50 |
2% |
+6.0 |
5% |
* |
|
| 4+ months |
+550 |
2% |
440 |
10% |
* |
|
+50 |
2% |
+2.5 |
7% |
* |
|
* No increment
Minerals
| Age |
Copper
mg/d |
% in an egg |
Iodine
mg/d |
% in an egg |
Selenium
mg/d |
% in an egg |
| 7-9 months |
0.3 |
13% |
60 |
45% |
10 |
60% |
| 10-12 months |
0.3 |
13% |
60 |
45% |
10 |
60% |
| 1-3 years |
0.4 |
10% |
70 |
39% |
15 |
40% |
| 4-6 years |
0.6 |
7% |
100 |
27% |
20 |
30% |
| 7-10 years |
0.7 |
6% |
110 |
25% |
30 |
20% |
| Males |
| 11-14 years |
0.8 |
5% |
130 |
21% |
45 |
13% |
| 15-18 years |
1.0 |
4% |
140 |
19% |
70 |
9% |
| 19-50 years |
1.2 |
3% |
140 |
19% |
75 |
8% |
| 50+ years |
1.2 |
3% |
140 |
19% |
75 |
8% |
| Females |
| 11-14 years |
0.8 |
5% |
130 |
21% |
45 |
13% |
| 15-18 years |
1.0 |
4% |
140 |
19% |
60 |
10% |
| 19-50 years |
1.2 |
3% |
140 |
19% |
60 |
10% |
| 50+ years |
1.2 |
3% |
140 |
19% |
60 |
10% |
| |
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| Pregnancy |
* |
|
* |
|
* |
|
| Lactation |
| 0-4 months |
+0.3 |
3% |
* |
|
+15 |
8% |
| 4+ months |
+0.3 |
3% |
* |
|
+15 |
8% |
* No increment
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