Research shows that vitamin D supplement compliance is low among older adults in the Netherlands, with only 38% of women over 50 and 40% of elderly people taking supplements as recommended, compared to 71% of young children. According to Gram Research analysis of this 2026 cross-sectional study of 1,485 Dutch adults, the problem is even worse when considering correct dosage—only 30% of women and 35% of elderly supplement users took the recommended amount, meaning true compliance is around 11% for women and 14% for elderly people.
A new study from the Netherlands looked at how many people in three groups are actually taking vitamin D supplements as doctors recommend. Researchers checked data from over 1,400 people including young children, women over 50, and elderly adults. They found that 71% of young children take vitamin D supplements as advised, but only 38% of women over 50 and 40% of elderly people do. Even among those taking supplements, many aren’t taking the right amount. The study shows that while kids are doing well with vitamin D supplementation, there’s lots of room for improvement in helping older adults get enough of this important nutrient.
Key Statistics
A 2026 cross-sectional study of 1,485 Dutch adults found that only 38% of women ages 50-69 and 40% of elderly people ages 70-79 reported taking vitamin D supplements as recommended, compared to 71% of young children ages 1-3.
Among supplement users in the Netherlands study, only 30% of women over 50 and 35% of elderly people were taking the correct recommended dose of vitamin D, meaning actual compliance with full recommendations was approximately 11% and 14% respectively.
When asked generally about supplement use, 55% of Dutch women over 50 reported taking vitamin D supplements, but detailed dietary recalls showed only 38% actually used them, suggesting people overestimate their supplement compliance.
The Quick Take
- What they studied: How many people in three at-risk groups are actually following their doctor’s advice to take vitamin D supplements every day
- Who participated: 1,485 people from the Netherlands: 703 young children ages 1-3, 451 women ages 50-69, and 331 elderly people ages 70-79. Data came from a national food and nutrition survey conducted between 2019-2021
- Key finding: Only 71% of young children, 38% of women over 50, and 40% of elderly people reported taking vitamin D supplements. Among those who did take supplements, most weren’t taking the recommended dose
- What it means for you: If you’re a woman over 50 or elderly, there’s a good chance you’re not getting the vitamin D your body needs. Even if you take supplements, you might not be taking enough. Talk to your doctor about whether you should be taking vitamin D and what the right amount is for you
The Research Details
Researchers used information from the Dutch National Food and Consumption Survey, which tracks what people eat and drink. They looked at data collected between 2019 and 2021 from three groups: young children, middle-aged and older women, and elderly adults. The study asked people two ways about their supplement use: first with a general questionnaire asking if they took supplements, and second with detailed 24-hour dietary recalls where people reported exactly what supplements they took and how much. This two-step approach helped researchers get accurate information about supplement use.
The researchers specifically looked at vitamin D supplements in different forms—pure vitamin D, vitamin D combined with calcium, multivitamins with vitamin D, and other combinations. They compared what people reported taking to the official Dutch recommendations for vitamin D supplementation. The study was designed to understand how well people follow these recommendations in real life.
Understanding whether people actually take recommended supplements is just as important as knowing what the recommendations are. If doctors recommend vitamin D supplements but people don’t take them, the recommendations won’t help prevent vitamin D deficiency and related health problems. This study provides real-world information about the gap between what’s recommended and what people actually do, which helps public health officials figure out where to focus their efforts
This study used data from a nationally representative survey, which makes the findings more reliable than a small study. The researchers used two different methods to collect supplement information, which helps confirm accuracy. However, the study only looked at one point in time (2019-2021), so it doesn’t show whether supplement use changed over time. The study also relied on people’s memory of what they took, which can sometimes be inaccurate
What the Results Show
The study found big differences in vitamin D supplement use between the three groups. Young children had the highest compliance, with 71% taking vitamin D supplements as recommended. Women over 50 had much lower rates, with only 38% taking supplements. Elderly people were similar to women, with 40% taking supplements.
When researchers looked more carefully at people who were taking supplements, they found another problem: many weren’t taking the right amount. Among young children who took supplements, 70% were taking the correct recommended dose. But among women over 50 who took supplements, only 30% were taking the right amount. For elderly people, 35% of supplement users were taking the correct dose.
This means the real compliance numbers are even lower when you account for both taking supplements AND taking the right amount. For example, if 38% of women over 50 take supplements, but only 30% of those are taking the right dose, then only about 11% of all women over 50 are actually following the recommendation correctly.
The study also noted differences between what people reported on a general questionnaire versus what they reported in detailed dietary recalls. When asked generally about supplements, more people reported taking them (80% of children, 55% of women, 50% of elderly) compared to the detailed recalls. This suggests that people might overestimate their supplement use when asked casually, or they might take supplements occasionally rather than daily as recommended
According to Gram Research analysis, this is one of the first studies to look specifically at compliance with vitamin D recommendations in these three at-risk groups in the Netherlands. The findings align with other research showing that older adults are less likely to take supplements regularly compared to younger people. The low compliance rates in women over 50 and elderly people suggest this is a widespread problem that needs attention
The study only looked at data from one time period (2019-2021), so we don’t know if supplement use has changed since then. The study relied on people remembering and accurately reporting what supplements they took, which can be unreliable. The study didn’t ask why people weren’t taking supplements or what barriers they faced, so we don’t know whether the problem is cost, awareness, forgetting, or something else. Finally, the study only looked at supplement use, not actual vitamin D levels in people’s blood, so we don’t know if those taking supplements actually have adequate vitamin D status
The Bottom Line
If you’re a woman over 50 or elderly, ask your doctor whether you should be taking a vitamin D supplement. If your doctor recommends it, make sure you understand the correct dose and set up a system to remember to take it daily (such as putting it with your breakfast or setting a phone reminder). Young children appear to be doing well with supplementation, but parents should still confirm with their pediatrician that their child is taking the recommended amount. These recommendations are based on solid evidence that vitamin D is important for bone health and other body functions
This research is most relevant to women over 50, elderly adults, and parents of young children. Healthcare providers and public health officials should also pay attention, as the low compliance rates suggest current strategies for promoting vitamin D supplementation aren’t working well for older adults. If you have kidney disease, certain cancers, or other health conditions, talk to your doctor before starting vitamin D supplements
Vitamin D works gradually in your body. It takes weeks to months of regular supplementation to build up adequate vitamin D levels. You probably won’t notice dramatic changes, but over time, proper vitamin D levels support bone strength, immune function, and overall health. Your doctor can check your vitamin D level with a blood test if you want to know whether supplementation is working
Frequently Asked Questions
How many people actually take vitamin D supplements as their doctor recommends?
A 2026 Dutch study found that 71% of young children take vitamin D supplements as advised, but only 38% of women over 50 and 40% of elderly people do. When accounting for correct dosage, compliance drops to about 11% for women and 14% for elderly people.
Do I need to take a vitamin D supplement if I’m over 50?
The Netherlands recommends vitamin D supplements for women over 50 and elderly adults regardless of sun exposure. Talk to your doctor about whether you specifically need supplementation, as individual needs vary based on diet, sun exposure, and health conditions.
What’s the right dose of vitamin D I should be taking?
The correct dose depends on your age and health status. Ask your doctor for the specific recommendation for you. The study found that many people taking supplements weren’t taking the recommended amount, so it’s important to confirm the right dose with your healthcare provider.
How long does it take to see benefits from taking vitamin D supplements?
Vitamin D builds up gradually in your body over weeks to months of consistent supplementation. You won’t notice immediate changes, but regular intake supports bone health and immune function. Your doctor can check your vitamin D level with a blood test after 2-3 months.
Why do so few older adults take vitamin D supplements if doctors recommend them?
This study didn’t investigate reasons for low compliance, but common barriers include forgetting to take daily supplements, cost, lack of awareness about recommendations, and not understanding why vitamin D matters. Researchers recommend studying these barriers to improve compliance.
Want to Apply This Research?
- Set up a daily reminder to take your vitamin D supplement at the same time each day (for example, with breakfast). Track whether you took it each day using a simple yes/no checklist in your app. Aim for 100% compliance over a month to see if you can build the habit
- Link your vitamin D supplement to an existing daily habit you already do (like brushing your teeth or having coffee). Keep your supplement bottle in a visible place, like next to your toothbrush or on the kitchen counter. If you forget, don’t skip doses—just take it the next day and continue the routine
- Track your supplement use weekly and monthly to identify patterns. If you’re struggling to remember, try different reminder methods (phone alarm, pill organizer, calendar marking). After 3 months of consistent use, ask your doctor to check your vitamin D level with a blood test to confirm the supplementation is working
This research describes supplement use patterns in the Netherlands and may not apply to other countries with different recommendations or populations. This article is for educational purposes and should not replace medical advice. Before starting, stopping, or changing any vitamin D supplementation, consult with your healthcare provider, especially if you have kidney disease, heart disease, or take medications that interact with vitamin D. Individual vitamin D needs vary based on age, health status, diet, and sun exposure. A healthcare provider can determine the appropriate dose for your specific situation.
This research translation is published by Gram Research, the science division of Gram, an AI-powered nutrition tracking app.