Published by Actually Sleeping · Reviewed by Dr. Samantha Abrahamson, PharmD · Review policy · Updated 2026-11-10

Do vitamin D drops or probiotics affect a baby’s sleep?

Not in any proven way. The AAP recommends vitamin D for most babies for bone health, not sleep, and a randomized trial found a higher vitamin D dose gave no sleep benefit over the standard dose. Probiotic trials for colic have mixed results, and the FDA has approved no probiotic as a drug for infants. Ask your pediatrician before changing either.

A note on scope: Dr. Sam is a Doctor of Pharmacy and a licensed pharmacist, not a physician. This page explains in general terms how a medicine, supplement or remedy relates to sleep; it does not replace your child’s pediatrician. Check with your child’s pediatrician before giving your child any medicine, supplement or remedy, and follow the product label.

The short answer

Vitamin D drops are a routine part of infant care for many babies, and you should keep giving them as your pediatrician advised. They are not a sleep treatment, and giving more will not improve sleep. Probiotics are a different story: optional, variable products with mixed evidence for colic and no proven effect on sleep.

When a supplement question is really a sleep question, Actually Sleeping can help. The practice is led by Dr. Sam, a pharmacist, so supplement questions are taken seriously and medical ones go to your pediatrician, while the plan works on how your baby sleeps.

Vitamin D: what the evidence says

Why babies get it. The AAP recommends that all infants receive a vitamin D supplement, except babies drinking enough vitamin D-fortified formula. Breastfed babies specifically need it. Your pediatrician will tell you which product and how much.
Sleep. In the VIDI randomized trial, infants given a higher daily vitamin D dose had no sleep benefit up to age 2 compared with the standard dose. The researchers saw an association between higher vitamin D blood levels and better sleep, but an association does not show that vitamin D causes better sleep.
More is not better. The AAP notes that fat-soluble vitamins are stored in the body and at very high levels could make a child sick. Use the measuring device that comes with the product and never double up.

Probiotics: what the evidence says

Colic trials are mixed. Trials of one probiotic strain found benefits in breastfed babies with colic, while a later trial that included formula-fed babies found no benefit. Less crying, where it happened, is not the same as longer sleep.
Regulation. The FDA states it has not approved any probiotic product for use as a drug or biological product in infants of any age. Probiotics are commonly sold as foods or dietary supplements.
Preterm babies. In 2023 the FDA warned that probiotic products given to hospitalized preterm infants had contributed to serious infections, including one infant death. If your baby was born early, do not start a probiotic without your pediatrician.

Why parents notice a change

Babies change fast. A new supplement often starts in the same weeks as a growth spurt, a shift in naps or the natural easing of colic around 3 to 4 months. It is easy to credit the drops with a change the calendar made.

What to ask the pediatrician

“Does my baby need vitamin D drops, given how they are fed?”
“Is a probiotic reasonable for my baby’s crying, and which one, if any?”
“My baby was born early. Is any supplement unsafe for them?”

Medicine is not the answer to a sleep problem

Keep giving vitamin D as your pediatrician advised. For sleep, look somewhere else: at the schedule, the routine and how your baby falls asleep. Those are different for every baby, which is why age charts such as wake windows by age are only a starting point.

Actually Sleeping turns them into a plan for your baby: age, feeds, temperament, current way of falling asleep and your family’s day. You get bootcamp-style coaching before the first night, daily 1:1 check-ins and naps coached until solid, and the plan never asks you to drop a night feed. Parents describe the change in the client video reviews.

Book the free consultation to talk through your baby’s sleep.

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Frequently asked

Does vitamin D make babies sleep better?

There is no proof that it does. A randomized trial found a higher vitamin D dose gave no sleep benefit over the standard dose up to age 2. Give vitamin D for bone health as your pediatrician advises.

Can vitamin D drops keep my baby awake?

There is no good evidence of that at recommended amounts. Give the drops at whatever time of day is easiest to remember. Use only the product and amount your pediatrician recommends, and never double up.

Do probiotics help a colicky baby sleep?

Evidence is mixed. Trials of one strain found less crying in some breastfed babies, but not in a trial that included formula-fed babies, and none showed a clear sleep benefit. The FDA has approved no probiotic as a drug for infants.

Are probiotics safe for premature babies?

Talk to your pediatrician first. In 2023 the FDA warned that probiotic products given to hospitalized preterm infants contributed to serious infections, including a death. The FDA also states it has not approved any probiotic as a drug for infants of any age.