Expert Nutrition

Biotin

Biotin, which is closely related to folate, pantothenic acid and vitamin B12 is a coenzyme that is essential for the body to utilise energy stores that are created through the metabolism of carbohydrate and the biosynthesis of fatty acids and proteins. Just like other B-complex vitamins Biotin is water soluble.

A deficiency in biotin is rare as biotin is found in a wide range of food sources and there is a significant amount of the vitamin synthesised through intestinal bacteria reducing the need for it in our diet. Biotin deficiencies however can be seen in infants who lack the intestinal bacteria and adults who consume large amounts of uncooked egg whites (often practiced by body builders) which contain avidin that binds to biotin in the gut preventing absorption. The good news is that avidin is destroyed during the heating process and so eating cooked eggs is not a risk factor for a biotin deficiency.

Good dietary sources of biotin include yeast, egg yolks, soy beans, liver, and to a lesser extent meat, fruits and vegetables.

There is no set recommended dietary intake for biotin as a large portion of the vitamin is created by bacteria in the intestines and requirements are hard to determine, however a recent publication by the National Health and Medical Council has set Adequate Intake levels which are summarised in the table below. Excess intake of biotin through diet or supplementation has not been reported to accumulate to toxic levels and as such there is no suggested upper limit of intake.

Biotin back to Vitamins


Dietary Recommendations For Biotin

Please refer to the following definitions when interpreting these recommendations:

RDI-Recommended Daily Intake
The average daily intake level that is sufficient to meet the nutritional requirements of nearly all (97-98%) health individuals in a particular life stage and gender group.

AI-Adequate Intake (used when an RDI cannot be determined)
The average daily nutrient intake level based on observed or experimentally-determined approximations or estimates of nutrient intake by a group (or groups) of apparently healthy people that are assumed to be adequate.

UL-Upper Limit of Intake
The highest average daily nutrient intake level likely to pose no adverse health effects to almost all individuals in the general population. As intake increases above the UL, the potential risk of adverse effects increases.

RECOMMENDATIONS BY LIFE STAGE AND GENDER - Biotin

InfantsAI
0-6 months5 µg/day
7-12 months 6 µg/day

Children and AdolescentsAI
All
1-3 years 8 µg/day
4-8 years 12 µg/day

Boys
9-13 years 20 µg/day
14-18 years 30 µg/day

Girls
9-13 years 20 µg/day
14-18 years 25 µg/day

AdultsAI
Men
19-30 years 30 µg/day
31-50 years 30 µg/day
51-70 years 30 µg/day
>70 years 30 µg/day

Women
19-30 years 25 µg/day
31-50 years 25 µg/day
51-70 years 25 µg/day
>70 years 25 µg/day

Pregnancy
14-18 years 30 µg/day
19-30 years 30 µg/day
31-50 years 30 µg/day

Lactation
14-18 years 35 µg/day
19-30 years 35 µg/day
31-50 years 35 µg/day

Source: National Health and Medical Research Council. Nutrient Reference Values for Australia and New Zealand. Department of Health and Ageing, Canberra 2006, copyright Commonwealth of Australia reproduced by permission.


References:
1. Stanton R. Foods that harm, foods that heal: An A-Z guide to safe and healthy eating. Readers Digest; 2006, pp378-382.
2. MacWilliam, L.D. Comparative Guide to Nutritional Supplements. Northern Dimensions Publishing; 2005 pp49.
3. Mann, J., Truswell, S. Essentials of Human Nutrition. Oxford Medical Publications, New York. 2000; pp 200-201.
4. Wahlqvist, M.L., et al. Australia and New Zealand: Food and Nutrition. 2nd Ed. Allen and Unwin, Sydney; 2002, pp 208-209.
5. National Health and Medical Research Council. Nutrient Reference Values for Australia and New Zealand. Department of Health and Ageing, Canberra 2006, copyright Commonwealth of Australia reproduced by permission.


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