Biotin or vitamin B-7 is a water-soluble vitamin. It is an essential nutrient that helps convert food into fuel for the body and helps metabolize carbohydrates, fats, and proteins.
Biotin also plays a role in gene regulation and cell signaling and is associated with healthy hair, nails, and skin. It is important for the developing fetus in pregnant women and for liver health.
As biotin is water-soluble, it is not stored in the body. However, biotin can be manufactured by bacteria in the gut, taken as a dietary supplement, or obtained by eating certain foods.
Salmon, avocado, nuts and seeds are some of the foods rich in biotin.
The Office of Dietary Supplements state that an adequate intake (AI) of biotin for adults is 30 micrograms (mcg) daily, with breastfeeding women requiring 35 mcg.
How much biotin food retains is affected by the processing techniques. For example, canning can reduce biotin levels. Also, some researchsuggests that it is difficult to estimate the biotin content of foods due to inaccuracies and gaps in the data of food composition tables.
However, foods considered some of the richest sources of biotin include the following:
1. Liver and other meats
As most biotin is stored in the liver, eating animal liver is one of the simplest ways to increase biotin in a diet. A 3-ounce serving of cooked beef liver contains approximately 30 mcg of biotin. Other organ meats, such as kidney, also contain high levels.
Other types of meat contain less biotin than organ meats, but they are still a relatively good source of the vitamin. For example, a 3-ounce pork chop provides nearly 4 mcg, as does a cooked hamburger patty.
A 3-ounce serving of meat is approximately the size of a deck of cards.
2. Egg yolk
Egg yolks are another biotin-rich food with 1 whole, cooked egg providing up to 10 mcg.
For maximum biotin intake, eggs should be cooked before eating. This is because of a protein called dietary avidin, which is found in raw egg whites and binds to biotin, stopping it from being absorbed by the body.
Cooking separates the biotin from the avidin to allow it to be absorbed in the digestive tract.
Both brewer’s yeast and nutritional yeast are good sources of biotin, although the amount can vary widely.
Brewer’s yeast is an active yeast that is used to make beer and bread, while nutritional yeast is inactive and used to add a cheesy or nutty flavor to foods.
According to the Linus Pauling Institute at Oregon State University, 7 grams (g) of yeast contain between 1.4 and 14 mcg of biotin.
4. Nuts and seeds
Biotin content varies with the type of nut or seed, but both these foods types are a good source of the vitamin.
Almonds, peanuts, walnuts, and pecans all contribute to biotin intake, with a quarter-cup of roasted almonds containing 1.5 mcg. A quarter-cup of roasted sunflower seeds contains 2.6 mcg.
Also, nuts and seeds contain other nutrients, including vitamin E, which also benefit skin and hair health.
Salmon is a fatty fish that is rich in protein, omega-3s, and other nutrients that contribute to healthy skin and strong hair. It is also a good source of biotin, with a 3-ounce cooked serving containing up to 5 mcg.
Milk, cheese, and yogurt all contain biotin in varying amounts. In a comparative study of 23 types of cheese, it was found that Camembert cheese and blue cheese were among the most biotin-rich.
Although this latter study dates back several decades, the National Institutes of Health confirm that cheddar cheese provides 0.4 mcg of biotin per ounce, a cup of 2 percent milk has 0.3 mcg, and a cup of plain yogurt contains 0.2 mcg.
One whole avocado contains between 2 to 6 mcg of biotin, according to some sources. Like nuts and seeds, avocado is a rich source of vitamin E.
8. Sweet potato
Sweet potatoes are among the highest biotin-containing vegetables. A half-cup of cooked sweet potato contains approximately 2.4 mcg of biotin and just 90 calories.
Sweet potatoes are also rich in beta-carotene, which the body converts to vitamin A, making them another good choice for those who wish to improve the health of their skin.
One cup of raw cauliflower provides up to up to 4 mcg of biotin. For an easy way to consume raw cauliflower, mix it in a food processor until it resembles breadcrumbs, and serve it instead of cooked rice, add to a salad or mix into cooked grains to make a pilaf.