Nutrient

Benefits 

Food Sources

Biotin

• Water-soluble B vitamin needed for the release of energy from food. This is because it acts as a coenzyme in the breakdown and utilisation of protein, fat and carbohydrate.

• Also important for cell growth and replication because it helps in the manufacture of DNA, RNA and fatty acids.

• Required in sufficient amounts for healthy hair and skin, and may help regulate insulin sensitivity and the activity of enzymes involved in glucose metabolism.

• Good sources include bananas, eggs and white fish.

• Also found in brewer’s yeast, milk, meat, poultry, soybeans, whole grains, mushrooms and peanuts.

Carotenoids

• Act as powerful antioxidants which help neutralise free radicals caused by sunlight and other environmental factors. Free radicals cause damage by interacting with cell membranes, proteins and cell DNA.

• The six most common carotenoids are: betacarotene, alphacarotene, cryptoxanthin, zeaxanthin, lycopene and lutein. They help maintain a healthy immune system, especially cellular immunity where free radicals may alter cell DNA, causing cells to change

• Good sources include tomatoes, watermelon, spinach, carrots, peas, broccoli, oranges, pumpkin, peaches, apricots, cantaloupe, red peppers and mangos.

Nutrient 

Intake levels 

RDAs & Maximum Intake Levels for Long Term Supplementation (Based on 60kg Adult)

Effects of Deficiency

Biotin

• RDA = 150mcg

• Max daily intake level = 900mcg (source EMV 2003)

• Because biotin is a water-soluble vitamin, any excess is excreted by the body making it safe to take at relatively high doses.

Biotin deficiency is very rare in adults since biotin is manufactured by bacteria in the intestines. However, if deficiency does occur it may cause anaemia, depression, hair loss, high blood sugar, inflammation of the skin, insomnia, loss of appetite, muscular pain, nausea and a sore tongue.

Carotenoids

• The RDA and recommended daily intake for carotenoids are not established.

People who don’t eat the recommended five portions of fruit and vegetables per day are probably not getting enough carotenoids. There are no obvious symptoms of deficiency, but a lack of carotenoids in the diet may have a negative impact on long-term health.