KEY TAKEAWAYS

  • Biotin is a B vitamin that helps your body break down carbs, fats, and proteins.
  • About one-third of pregnant women may develop low biotin levels, even if they eat enough.
  • Biotin supports early embryo development, including palate formation and cell growth.
  • Too much biotin can interfere with blood tests, so always follow your doctor’s guidance.
  • Biotinidase deficiency is a genetic disorder where the body can’t recycle biotin, but it can usually be managed with supplementation if caught early.
A pregnant woman with ultrasound scan

Biotin is often thought of as the vitamin for healthy hair, glowing skin, and strong nails. But when you are pregnant, this B vitamin has a far more important role. Biotin supports metabolism, cell growth, and normal development of your baby in the womb. That is why most prenatal vitamins include it.

During pregnancy, your body needs extra support to keep up with the changes of growing a baby. Even if you are eating well, your biotin levels may drop. This makes it important to understand how biotin when pregnant works, what deficiency can look like, and how rare genetic conditions like Biotinidase deficiency can affect newborns.

What is Biotin?

Biotin, also known as vitamin B7, is a water-soluble vitamin that helps your body turn food into energy. It works with enzymes that break down carbohydrates, fats, and proteins. Without biotin, your body would struggle to use these nutrients for energy and growth.

Why Biotin When Pregnant Matters

Stages human embryonic development

Many women wonder why biotin is in prenatal vitamins if the evidence for hair and skin benefits is not strong. The reason is because biotin supports basic metabolic functions that are essential during pregnancy.

Because you may not know you’re pregnant right away, taking a prenatal vitamin with biotin (and folic acid) before conception gives your baby the best start.

During pregnancy, your body’s metabolism speeds up to support your growing baby. Studies suggest that biotin when pregnant may be especially important for:

1. Early embryo development

One laboratory study using human cells found that biotin may be important for palate formation. This suggests that biotin has a role in preventing certain developmental issues, though more research is needed in humans.

2. Ovarian function

In one study, researchers found that biotin levels were higher in ovarian follicles just before ovulation, which may help prepare the body for fertilization and early growth. Other animal studies have linked biotin deficiency with birth defects such as cleft palate and skeletal problems.

3. Sperm health

Another study looked at frozen sperm in a laboratory setting. When biotin was added to the culture, sperm showed better movement, higher fertilization rates, and better early embryo development. This does not prove the same happens in the body, but it does show how biotin could be involved from the very start of life.

SUMMARY

Biotin is a special vitamin that helps moms and babies stay healthy during pregnancy. It gives the body energy and helps tiny babies grow the right way, even before a mom knows she is pregnant. Doctors put biotin in prenatal vitamins because it can help with things like the baby’s mouth and bones forming, the mom’s body getting ready for a baby, and even helping sperm move better.

Symptoms of Low Biotin

Biotin deficiency is rare in the general population, but pregnancy changes how your body uses vitamins. About one in three pregnant women may develop mild deficiency. Symptoms can include:

  • Hair loss
  • Brittle nails
  • Skin rashes
  • Low energy
  • Neurological symptoms in severe cases

These signs are not unique to biotin deficiency, so they can be confused with other health problems.

Causes of Low Biotin When Pregnant

Researchers do not fully understand why biotin levels fall in pregnancy, but studies show that it happens even when women eat enough. Nursing mothers also show lower biotin levels, which is why experts recommend staying on prenatal vitamins during breastfeeding.

Other causes of low biotin include certain medications, long-term alcohol use, or rare genetic conditions such as Biotinidase deficiency.

How Much Biotin Do You Need?

The National Academies of Sciences recommends 30 micrograms a day for adult women, including during pregnancy. For breastfeeding women, the recommendation is 35 micrograms.

Most prenatal vitamins include this amount. However, since a third of women may still experience lower levels, it is important to talk with your doctor about your specific needs.

Important! Taking too much is not safe. High doses of biotin can interfere with important blood tests such as thyroid function and pregnancy hormone levels. The FDA has warned that incorrect results can affect diagnosis and treatment. Always tell your doctor if you are taking a supplement that contains biotin.

Biotinidase Deficiency

While most cases of biotin deficiency in pregnancy are mild, some newborns may inherit Biotinidase deficiency, a genetic disorder that prevents the body from recycling biotin.

What Happens in Biotinidase Deficiency?

Normally, the enzyme biotinidase helps release free biotin for the body to use. In Biotinidase deficiency, mutations in the BTD gene stop this recycling process, leading to secondary biotin deficiency.

Symptoms

  • Seizures and developmental delays
  • Low muscle tone (hypotonia)
  • Vision or hearing problems
  • Rashes and hair loss
  • In severe cases, coma or death if untreated

Treatment

The good news is that biotinidase deficiency is treatable. Lifelong biotin supplementation can prevent or reverse symptoms if started early. Newborn screening programs often test for it, making early diagnosis possible.

Foods Rich in Biotin

You can get biotin from many everyday foods, including:

  • Eggs (cooked, since raw egg whites contain a protein that blocks absorption)
  • Salmon and tuna
  • Nuts and seeds
  • Whole grains
  • Sweet potatoes and spinach

Eating a varied diet plus a prenatal vitamin usually provides enough biotin when you are pregnant. Still, since levels can fall even with normal intake, supplements play an important role.

Could Symptoms Be Something Else?

Because signs of low biotin are vague, they are often mistaken for other conditions. Hair loss and fatigue, for example, could be due to iron deficiency, thyroid problems, zinc deficiency, or normal postpartum changes.

If you notice symptoms, your doctor may test your blood to rule out these other causes before checking for biotin deficiency.

The Bottom Line

Biotin plays a vital role in metabolism, energy production, and cell growth. During pregnancy, biotin when pregnant supports the healthy development of your baby.

While deficiency is rare, up to a third of women may experience low levels during pregnancy or breastfeeding. That is why biotin when pregnant are important. Rare conditions like Biotinidase deficiency show how serious a lack of this vitamin can be, but with early treatment, children with this condition can live healthy lives.

The best way to protect yourself and your baby is to eat a balanced diet, take a prenatal vitamin, and talk with your doctor about any supplements you use.