Best food groups: Enriched cereal grains, meat, eggs, dairy
Also consider: Cereal, chocolate, legumes, dairy, nuts, beef liver, yeast
What is biotin and why is it so important? Biotin, or vitamin B7, is a water-soluble B vitamin that was first discovered in 1927 but took nearly forty years to be fully recognized as a nutrient. Biotin is required by all organisms. It can be created by bacteria, yeasts, molds, algae, and some plants, but not humans. It is important in the maintenance of all cells in the body and supports healthy skin and hair, the nervous and digestive systems, and carbohydrate metabolism.
Deficiencies, once thought to be rare, are a concern and may present as dry, scaly skin, nausea, anorexia, dermatitis, hair loss, conjunctivitis, depression, and hallucinations.
Did you know? Biotin was once referred to as several different terms, such as coenzyme R, vitamin H, and "the anti–egg white factor." (Raw egg whites contain a biotin binding protein called avidin; however, when egg whites are cooked, avidin is destroyed.)
How much is enough?
The DV for biotin is 300 mcg, based on a 2,000-calorie diet.
Biotin is not known to be toxic. Doses up to 200,000 mcg per day for short periods of time and doses up to 5,000 mcg per day for up to two years were all reported to be well tolerated. Therefore, the Institutes of Medicine (IOM) have not established a UL for biotin.
Supplements: High doses have been used to treat peripheral neuropathy, elevated blood glucose, insulin resistance, and elevated blood lipids. Popular use of biotin in the dietary supplement form is to treat hair loss or to make hair thicker.
To date, the research to support its use for this purpose is rather weak.
1. Chicken Liver
No other food even comes close, including livers from other animal sources, in supplying biotin in the diet. Chicken liver is also an excellent source of choline (255 percent of DV), folate (127 percent of DV), iron, niacin, pantothenic acid, phosphorus, riboflavin, selenium (over 100 percent of DV), vitamin A, vitamin B12 (247 percent of DV), and zinc; and a good source of the phytochemicals lutein, lycopene, and zeaxanthin. It's even fairly low in saturated fat! If it weren't for that pesky ol' 495 mg of cholesterol per serving, chicken liver might be one the healthiest foods in the whole book! Research suggests that many pregnant women are marginally biotin deficient and that this deficiency can lead to birth defects. Certainly, taking a prenatal formula can address a biotin deficiency; however, also eating biotin-rich foods such as chicken liver provides an abundance of this and other nutrients in a fairly small portion. In addition, biotin helps in the formation of heme, which aids in iron absorption.
2. Beef Liver
For the healthy scoop on beef liver, see page 286. Animal research has shown that both biotin and chromium deficiencies can contribute to poor glucose management and reduced insulin sensitivity, leading to metabolic syndrome and diabetes. Beef liver is a good source of both biotin and chromium.
3. Eggs
Eggs are a good source of phosphorus, protein, riboflavin, and vitamin D. Biotin is instrumental in gene expression that protects the brain. Eggs not only provide a source of biotin but also brain-friendly choline, which may help in improving cognition.
4. Pink Salmon
For the lowdown on salmon's healthy properties, see page 291. Biotin controls gene expression that's critical in the regulation of blood glucose and cholesterol production. A diet that includes biotin and omega-3 fatty acid–containing foods, such as salmon, may help control lipid and blood glucose disorders.
5. Peanuts
One ounce of peanuts is an excellent source of manganese and niacin, and a good source of copper, fiber, folate, magnesium, phosphorus, thiamine, vitamin E, and zinc. A human cell study found that lymphoma cancer cells that were biotin deficient were more resistant to the killing effects of the chemotherapeutic drugs doxorubicin and vinblastine. Peanuts are a nutritious snack that contains biotin as well as a host of nutrients that help bolster the nutrition status of cancer patients undergoing chemotherapy.
6. Pork Chop
For more about the healthy properties of lean pork, see page 290. Lean protein, such as pork, has been shown to help control blood glucose, manage weight by increasing satiety, and also help preserve lean muscle tissue. There are seven cuts of pork that qualify as "lean" (under 10 grams of fat). The fat in lean pork is made up of mostly trans fat–free mono- and polyunsaturated fat, which fits well into a heart-healthy diet.
7. Mushrooms
For more on the health benefits of mushrooms, see pages 14, 20, and 289. For the vegetarians out there or those who simply want to reduce their meat intake, mushrooms offer a real solution. A study that swapped out calorie-dense meats and substituted mushrooms found that calorie intake was significantly higher when meat meals were consumed, but the volume of food between the meat and mushroom meals were the same. The best news is that most subjects did not rate palatability, appetite, or the feeling of being full and satisfied for the mushroom meals any differently than for the meat meals.
Source: USDA National Nutrient Database for Standard Reference, Release 24