4364.0.55.010 - Australian Health Survey: Nutrition - Supplements, 2011-12  
Latest ISSUE Released at 11:30 AM (CANBERRA TIME) 29/04/2015  First Issue
   Page tools: Print Print Page Print all pages in this productPrint All RSS Feed RSS Bookmark and Share Search this Product



IRON SUPPLEMENT INTAKE

INTRODUCTION

Iron is responsible for transporting oxygen in the blood to tissues throughout the body. It is also involved in the immune system, muscle function and cognitive functioning. Iron is found in a range of food sources, with cereal products and meat, poultry and game products and dishes being the primary sources in the Australian food supply. 1

A key finding from previous analysis of nutrition data from the Australian Health Survey was that one in eight people (13%) aged two years and over did not meet their iron requirements based on their intakes from food. Females were considerably more likely than males to have inadequate iron intakes, with 23% not meeting the requirements compared with 3% respectively (See Australian Health Survey: Usual Nutrient Intakes, 2011-12, cat. no. 4364.0.55.008).

This chapter presents information on Australians' consumption of iron from supplements, including the effect on overall iron intakes due to this supplementation. Women who were pregnant or breast feeding have been excluded from analysis in this article as they have different requirements. 2

How much iron is recommended?

The National Health and Medical Research Council (NHMRC) describes the Estimated Average Requirements (EARs) for iron, which are the daily levels of iron estimated to meet the requirements of half the healthy individuals in a particular life stage and gender group. 3 Iron requirements are higher during periods of rapid growth, such as childhood, adolescence and during pregnancy, as well as for females who menstruate.
NHMRC, Estimated Average Requirements - Iron

Estimated Average Requirement

Males
Females
Age group (years)
mg/day
mg/day

2-8
4
4
9-13
6
6
14-18
8
8
19-50
6
8
51 and over
6
5

Source: National Health and Medical Research Council 2006, Nutrient Reference Values for Australia and New Zealand, Canberra: National Health and Medical Research Council <http://www.nrv.gov.au/nutrients/iron>

WHO CONSUMED IRON FROM SUPPLEMENTS?

In 2011-12, 1.3 million females aged 2 years and over (13%), had some level of intake of iron from supplements (8% of 2-18 year olds, 15% of 19-50 year olds, and 14% of those aged 51 years and over) compared with 9% or approximately 960,000 males (8% of 2-18 year olds, 10% of 19-50 year olds and 8% of those aged 51 years and over).

Graph Image for Persons aged 2 years and over - Taking iron from supplements(a)(b), 2011-2012

Footnote(s): (a) On the day prior to interview. (b) Excludes pregnant and breast feeding females.

Source(s): National Nutrition and Physical Activity Survey, 2011-12



Range of iron intakes from supplements

Reported intakes of iron from dietary supplements on the day before interview varied from scant traces up to above 100mg for some individuals. The distribution of intakes is skewed for most age and sex groups. For example, the median intake of iron from supplements for females aged 19-30 years was 5mg, which is considerably lower than the average of 12mg.



Table 1: Intakes of iron from supplements(a)(b)(c), 2011-12

Age group (years)

2-3
4-8
9-13
14-18
19-30
31-50
51-70
71 years and over
Total 2 years and over

MalesAverage
mg
3
3
4
4
8
7
4
6
6
Median
mg
2
3
4
4
5
5
4
4
4
FemalesAverage
mg
3
3
5
10
12
8
5
6
7
Median
mg
2
2
2
7
5
5
5
5
5

(a) On the day prior to interview. (b) Excludes pregnant and breast feeding females. (c) For people who had taken iron from supplements.
Source: National Nutrition and Physical Activity Survey, 2011-12


The following graph shows the proportion of females aged 19-30 years who had consumed iron from supplements by various amounts on the day prior to interview. Just over one in five (22%) of these who consumed iron from supplements took 4mg or less, while there was a peak of 34% just above 5mg.

Females aged 19-30 years - amount of iron consumed from supplements, 2011-12

AVERAGE IRON INTAKES

How much iron do people consume?

In 2011-12, average amounts of iron consumed from foods and beverages only were 12.2mg for males aged 2 years and over and 9.3mg for females aged 2 years and over on the day prior to interview. When supplements were taken into account, average iron intakes increased to 12.7mg and 10.3mg for males and females respectively.

The effect of supplementation varied by age and sex, being greatest for females aged 19-50 years. In 2011-12, females aged 19-30 years consumed an average 9.5mg of iron from foods and beverages only on the day prior to interview, and when iron from supplements were taken into account this increased to 11.1mg. Similarly, iron intakes for women aged 31-50 years increased from 9.4mg to 10.7mg when supplementation was taken into account.

Average iron intake from foods, beverages and supplements - males, 2011-12

Average iron intake from foods, beverages and supplements - females, 2011-12

HOW MUCH DIFFERENCE DOES IRON FROM SUPPLEMENTS MAKE?

This section analyses median intakes of iron to understand the effect of taking supplements.

While those who consumed iron from supplements appear to have higher intakes from foods and beverages, these differences are not significant with the exception of males aged 9-13 and 31-50 years.


Median iron intake from foods and beverages - males, 2011-12
Median iron intake from foods and beverages - females, 2011-12

When intakes from supplements were taken into account, people who had consumed iron from supplements had higher median intakes of iron than those who did not consume iron from supplements for all age and sex groups, with the exception of females aged 14-18 years.

For people who had consumed iron from supplements, median iron intakes on the day prior to interview were greater than the respective EARs for all age and sex groups, with the exception of females aged 14-18 years.


Median iron intake from foods, beverages and supplements - males, 2011-12
Median iron intake from foods, beverages and supplements - females, 2011-12


PROPORTION OF PEOPLE MEETING THE ESTIMATED AVERAGE REQUIREMENT

Another way of considering the effect of taking iron from supplements is to compare individuals’ reported intakes of iron on the day prior to interview to the EAR. While no adjustment has been made to include information from the second 24-hour recall day, the following section provides an indicator of the effect of dietary supplements on intakes of iron. Table 2 shows the proportion of the population aged 2 years and over who had intakes of iron which met the EAR.

Overall, 72% of females aged 2 years and over had intakes of iron that were equal to or greater than the EAR based on their consumption of foods and beverages only. When consumption of iron from supplements was taken into account, this proportion increased slightly to 75%. For males the rates were similar (88% compared with 89%).

However, amongst adults who consumed iron from supplements the effect was more marked. In particular, 60% of females who consumed iron from supplements aged 31-50 years had intakes of iron that were equal to or greater than the EAR based on their consumption of foods and beverages only, but this proportion increased to 94% when iron from supplements was taken into account. Similarly, almost all males who consumed iron from supplements had intakes that were equal to or greater than the EAR.




Table 2: Proportion of people 2 years and over with intakes of iron that met the EAR(a)(b), 2011-12

People who did not take iron from supplements
People who did take iron from supplements
Total



Intake from foods and beverages only
Intake from foods and beverages only
Intake from foods, beverages and supplements
Intake from foods and beverages only
Intake from foods, beverages and supplements



Age group (years)
Proportion (%)

Males
2-3
77
90
100
79
80
4-8
95
91
100
95
96
9-13
90
100
100
91
91
14-18
70
92
100
72
72
19-30
88
96
99
89
89
31-50
89
95
100
90
90
51-70
89
97
99
90
90
71 years and over
89
86
100
88
90
Total 2 years and over
88
95
100
88
89

Females
2-3
87
93
100
87
88
4-8
93
99
100
94
94
9-13
74
77
92
74
76
14-18
52
62
100
53
55
19-30
59
55
87
59
63
31-50
57
60
94
57
63
51-70
90
92
99
90
91
71 years and over
87
90
96
87
88
Total 2 years and over
72
74
95
72
75

(a) On the day prior to interview.
(b) Excludes pregnant and breast feeding females.
Source: National Nutrition and Physical Activity Survey, 2011-12

SUMMARY

A key finding from Australian Health Survey: Usual Nutrient Intakes, 2011-12, (cat. no. 4364.0.55.008) was that 23% of females and 3% of males aged 2 years and over did not meet requirements for iron based on their usual intake from foods and beverages.

Analysis in this article found that when iron from supplements consumed on the day prior to interview was taken into account, average intakes of iron did not change a great deal. For females, average intakes increased from 9.3mg to 10.3mg with the inclusion of supplements, and from 12.2mg to 12.7mg for males. Therefore, while supplements were not included in the estimated usual intakes, they would have been unlikely to change levels of inadequate intakes across the entire population.

However, analysis also shows that for particular age and sex groups the consumption of iron from supplements had a greater effect, considerably increasing median intakes of iron on the day prior to interview. For example, for females aged 19-30 years and over who consumed iron from supplements, median intakes increased from 9.3mg from foods and beverages only to 15.7mg when supplements were taken into account.


ENDNOTES

1. Australian Bureau of Statistics, 2014, Australian Health Survey: Nutrition First Results - Foods and Nutrients, 2011-12, 'Table 10: Proportion of Nutrients from food groups', data cube: Excel spreadsheet, cat. no. 4364.0.55.007
2. National Health and Medical Research Council 2006, Nutrient Reference Values for Australia and New Zealand, Canberra: National Health and Medical Research Council <https://www.nrv.gov.au/nutrients/iron>, Last accessed 26/03/2015
3. National Health and Medical Research Council 2005, Nutrient Reference Values for Australia and New Zealand, Canberra: National Health and Medical Research Council <https://www.nrv.gov.au/node/50>, Last accessed 15/04/2015