Researchers studied whether vitamin D supplements could help children who have extra heartbeats caused by vitamin D deficiency. They looked at 46 children with two different types of heart rhythm problems. Kids with one type (RVOT) showed an 80% improvement in their extra heartbeats after taking vitamin D for 2 months. However, kids with the other type (left fascicular) didn’t see much improvement even after 3 months of supplements. This suggests that vitamin D might help some children with heart rhythm issues, but the effect depends on which type of problem they have.
The Quick Take
- What they studied: Whether giving vitamin D supplements to children with low vitamin D levels and extra heartbeats could reduce the number of extra heartbeats they experience.
- Who participated: 46 children (average age 10.6 years, mostly boys) who all had low vitamin D levels and were experiencing many extra heartbeats throughout the day. The children were split into two groups based on the type of extra heartbeats they had.
- Key finding: Children with RVOT-type extra heartbeats saw an 80% decrease in their extra heartbeats after 2 months of vitamin D supplements. Children with the other type (left fascicular) didn’t see significant improvement even after 3 months of supplements.
- What it means for you: If a child has low vitamin D and certain types of extra heartbeats, vitamin D supplements might help—but only for specific types. Talk to your doctor about whether your child should be tested for vitamin D deficiency if they’re experiencing heart rhythm issues. This is not a replacement for medical care.
The Research Details
This was a straightforward study where researchers identified children who had two problems at the same time: low vitamin D levels and extra heartbeats. They divided the children into two groups based on where the extra heartbeats were coming from in the heart (either the right side or left side). Then they gave all the children vitamin D supplements and measured how many extra heartbeats they had before and after treatment.
The researchers used heart monitors to count the exact number of extra heartbeats each child experienced in a 24-hour period. They also measured vitamin D levels in the blood before and after supplementation. This allowed them to see if raising vitamin D levels actually reduced the extra heartbeats.
This approach matters because it helps doctors understand whether vitamin D deficiency is actually causing the extra heartbeats in some children. By treating the vitamin D deficiency and watching what happens to the heartbeats, researchers can figure out if this is a real connection. The fact that they looked at two different types of extra heartbeats separately is important because it shows that vitamin D might help some children but not others.
This study has some strengths: it measured actual heart activity with monitors, it tracked vitamin D blood levels, and it looked at real children with the actual problem. However, the study is relatively small (46 children total), and the two groups were quite different in size (36 in one group, 10 in the other). There was no control group of children who didn’t get vitamin D to compare against, which would have made the results stronger. The study was published in a peer-reviewed medical journal, which means other experts reviewed it before publication.
What the Results Show
In the RVOT group (36 children), vitamin D supplementation produced dramatic results. Before treatment, these children were experiencing an average of 18,343 extra heartbeats per day. After 2 months of vitamin D supplements, their vitamin D levels rose from 23.5 to 41.6 ng/mL, and their extra heartbeats dropped to just 3,628 per day. This represents an 80% reduction—meaning four out of every five extra heartbeats went away.
In contrast, the left fascicular group (10 children) showed a very different response. These younger children (average age 6.9 years) started with 20,535 extra heartbeats per day and low vitamin D levels of 25.8 ng/mL. After 3 months of vitamin D supplements, their vitamin D levels increased significantly to 65.8 ng/mL—actually higher than the RVOT group. However, their extra heartbeats only decreased slightly to 19,207 per day, which is not a meaningful improvement.
This striking difference between the two groups is the most important finding. It suggests that vitamin D deficiency may be causing extra heartbeats in some children (those with RVOT-type) but not in others (those with left fascicular-type). The location of the extra heartbeats in the heart appears to determine whether vitamin D supplementation will help.
The study also revealed that the two groups of children were quite different in other ways. The RVOT group was older (average 12.7 years) compared to the left fascicular group (average 6.9 years). The RVOT group also had slightly lower vitamin D levels before treatment. These differences might explain why the groups responded so differently to vitamin D supplementation, though the researchers didn’t fully explore these possibilities.
Previous research has shown that vitamin D deficiency can cause extra heartbeats in both children and adults. This study supports that finding but adds important new information: the effect of vitamin D supplementation depends on the specific type of extra heartbeat. This is a more nuanced understanding than earlier research suggested. The 80% improvement in the RVOT group is particularly impressive and aligns with the theory that vitamin D plays a role in heart rhythm regulation.
Several important limitations should be considered. First, the study is small, especially the left fascicular group with only 10 children. Second, there was no control group—ideally, some children would have received a placebo (fake supplement) to compare against the real vitamin D. Third, the two groups were quite different in age and other characteristics, making direct comparison difficult. Fourth, the study didn’t follow children long-term to see if the benefits lasted after stopping supplements. Finally, the reasons why one group responded and the other didn’t remain unclear and would need further investigation.
The Bottom Line
If your child has been diagnosed with extra heartbeats and also has low vitamin D levels, ask your doctor about vitamin D supplementation—it may help, especially if the extra heartbeats are the RVOT type. However, vitamin D supplementation should not be the only treatment; your child should continue regular heart monitoring with a cardiologist. The evidence is moderate for RVOT-type extra heartbeats but weak for other types. Always work with your child’s doctor before starting any supplements.
This research is most relevant for parents of children who have been diagnosed with extra heartbeats and found to have low vitamin D levels. Children with RVOT-type extra heartbeats may benefit most. This is less relevant for children with normal vitamin D levels or other types of heart rhythm problems. Adults with similar issues should consult their own doctors, as this study only included children.
Based on this study, improvements in extra heartbeats appeared within 2-3 months of starting vitamin D supplements in the group that responded. However, you shouldn’t expect immediate results—give the treatment at least 2 months before evaluating effectiveness. Your child’s doctor will likely want to recheck vitamin D levels and heart rhythm after this period.
Want to Apply This Research?
- If your child is taking vitamin D supplements for this reason, track the number of heart palpitations (felt extra heartbeats) they notice per day or week in a simple log. Note the date, time of day, and how many episodes they felt. This gives you concrete data to discuss with your doctor and helps measure whether the supplement is working.
- Work with your doctor to establish a vitamin D supplementation routine—set a daily reminder for your child to take their supplement at the same time each day (often with a meal for better absorption). Also track vitamin D-rich foods in your child’s diet, such as fortified milk, fatty fish, and egg yolks, to complement the supplement.
- Schedule follow-up heart monitoring (like a Holter monitor) at 2 months and 3 months after starting vitamin D supplements to objectively measure changes in extra heartbeat frequency. Also recheck vitamin D blood levels at these intervals. Keep a symptom diary where your child notes any changes in how they feel, energy levels, or noticed heart palpitations. Share this data with your cardiologist at each visit.
This research summary is for educational purposes only and should not replace professional medical advice. Extra heartbeats in children can have various causes and require proper medical evaluation. Do not start, stop, or change any supplements or medications without consulting your child’s doctor or cardiologist. While this study suggests vitamin D supplementation may help some children with specific types of extra heartbeats, individual responses vary. Your healthcare provider can determine whether vitamin D testing and supplementation is appropriate for your child based on their specific situation. If your child experiences chest pain, shortness of breath, or fainting, seek immediate medical attention.
This research translation is published by Gram Research, the science division of Gram, an AI-powered nutrition tracking app.