According to Gram Research analysis, nearly 7 out of 10 military personnel and about 7.6 out of 10 civilians in Rio de Janeiro have low vitamin D levels, based on a cross-sectional study of 15,651 people conducted between 2018 and 2022. Men, older adults, and people tested during fall and summer months had better vitamin D status than women, younger people, and those tested in winter and spring.
Researchers in Brazil studied over 15,600 military personnel and their families to understand how much vitamin D they had in their bodies. They found that most people, whether military or civilian, had low vitamin D levels. Men and older adults had better vitamin D levels than women and younger people. People tested during fall and summer months also had higher vitamin D. The study shows that vitamin D deficiency is a widespread problem that needs attention through better nutrition and sun exposure strategies.
Key Statistics
A cross-sectional study of 15,651 Brazilian military personnel and civilians found that 68.9% of military personnel and 76.3% of civilians had vitamin D deficiency or insufficiency, with only about 3 in 10 military personnel and 2.4 in 10 civilians having adequate vitamin D levels.
Among 6,162 military personnel studied between 2018 and 2022, 21.3% had vitamin D deficiency and 47.6% had insufficiency, while among 9,399 civilians, 29.9% had deficiency and 46.4% had insufficiency.
Research from the Brazilian Air Force Hospital showed that men had significantly better vitamin D levels than women, and individuals tested during fall and summer months had higher vitamin D concentrations than those tested in winter and spring months.
The Quick Take
- What they studied: How much vitamin D people have in their bodies and what factors affect vitamin D levels in military and civilian populations
- Who participated: 15,651 people aged 18 to 60 years, including 6,162 military personnel and 9,399 civilians from the Brazilian Air Force in Rio de Janeiro, studied between 2018 and 2022
- Key finding: Nearly 7 out of 10 military personnel and about 7.6 out of 10 civilians had low vitamin D levels (either deficiency or insufficiency). Military personnel had slightly better vitamin D status than civilians.
- What it means for you: If you live in Brazil or similar climates, you may need to pay more attention to vitamin D intake through food, supplements, or safe sun exposure. This is especially important if you’re female, younger, or tested during winter months.
The Research Details
This was a cross-sectional study, which means researchers looked at a large group of people at one point in time to understand their vitamin D levels. They used blood test results from the Central Air Force Hospital database collected between 2018 and 2022. The researchers measured vitamin D using a laboratory method called chemiluminescence, which is a precise way to measure vitamin D in blood. They then compared vitamin D levels across different groups based on sex, age, military status, and the season when blood was collected.
This research approach is important because it shows real-world patterns in a large population rather than testing a specific treatment. By looking at thousands of people’s actual medical records, the researchers could identify which groups are most at risk for low vitamin D and what factors influence vitamin D levels.
The study is reliable because it included a very large sample size of over 15,600 people, used standardized laboratory testing methods, and covered a four-year period. The researchers used established medical criteria from both Brazilian and European experts to classify vitamin D levels. However, this study only shows associations, not cause-and-effect relationships, and the results may be specific to the Brazilian population studied.
What the Results Show
The study found that vitamin D deficiency is extremely common in both military and civilian populations. Among military personnel, 21.3% had vitamin D deficiency, 47.6% had insufficiency (low but not severely low), and only 31.1% had adequate vitamin D levels. Among civilians, the situation was slightly worse: 29.9% had deficiency, 46.4% had insufficiency, and only 23.7% had adequate levels. This means that nearly 7 out of every 10 military personnel and about 7.6 out of every 10 civilians had some degree of low vitamin D. The researchers also found that men had better vitamin D levels than women, and older adults had better levels than younger adults. People whose blood was tested during fall and summer months had higher vitamin D levels than those tested in winter and spring.
The study revealed important seasonal patterns in vitamin D levels. Collections done in fall and summer showed significantly better vitamin D status compared to winter and spring months, which makes sense because sun exposure is greater during warmer months. Age was another important factor, with older individuals showing better vitamin D levels than younger ones. This may be because older adults spend more time outdoors or have different dietary habits.
This research aligns with previous studies showing that vitamin D deficiency is a global health concern, particularly in populations with limited sun exposure or dietary sources of vitamin D. The findings are consistent with other research showing that women and younger people tend to have lower vitamin D levels. The high prevalence found in this Brazilian study is comparable to deficiency rates reported in other countries with similar latitudes and climates.
This study only looked at military personnel and their families in Rio de Janeiro, so the results may not apply to other regions of Brazil or other countries. The study was observational, meaning it shows what factors are associated with low vitamin D but cannot prove that these factors cause low vitamin D. The researchers did not have information about sun exposure habits, dietary intake, or supplement use, which are important factors affecting vitamin D levels. Additionally, the study did not examine why military personnel had slightly better vitamin D status than civilians, so the reasons for this difference remain unclear.
The Bottom Line
Based on this research, people should consider getting their vitamin D levels checked, especially if they are female, younger, or live in areas with limited winter sun exposure. Increasing vitamin D through food sources like fatty fish, egg yolks, and fortified dairy products is recommended. Safe sun exposure of 10 to 30 minutes several times per week may help improve vitamin D levels. For those with confirmed deficiency, vitamin D supplements may be necessary and should be discussed with a healthcare provider. Confidence level: High for the prevalence of deficiency; moderate for specific recommendations since this study did not test interventions.
Anyone living in Brazil or similar climates should pay attention to these findings, particularly women and younger adults who showed lower vitamin D levels. Military personnel and their families should be especially aware since the study was conducted in this population. People who spend limited time outdoors, work indoors, or have dietary restrictions should consider vitamin D monitoring.
Improving vitamin D levels through dietary changes or supplements typically takes 2 to 3 months to show measurable changes in blood tests. Seasonal improvements in vitamin D naturally occur during warmer months with increased sun exposure. Long-term benefits of adequate vitamin D on bone health and immune function develop over months to years.
Frequently Asked Questions
What percentage of people in Brazil have low vitamin D levels?
A 2022 study of 15,651 Brazilians found that 68.9% of military personnel and 76.3% of civilians had vitamin D deficiency or insufficiency, meaning only about 3 in 10 military and 2.4 in 10 civilians had adequate vitamin D levels.
Who is most likely to have vitamin D deficiency?
Women, younger adults, and people tested during winter and spring months showed the lowest vitamin D levels. Civilians also had higher deficiency rates than military personnel in this Brazilian study.
How can I improve my vitamin D levels naturally?
Increase sun exposure to 15 to 20 minutes during midday hours several times weekly, eat vitamin D-rich foods like fatty fish and fortified dairy, and consider supplements if blood tests show deficiency. Consult your doctor about appropriate vitamin D intake.
Does vitamin D change with the seasons?
Yes, this study found that people tested during fall and summer had significantly higher vitamin D levels than those tested in winter and spring, reflecting natural seasonal variations in sun exposure.
Should I get my vitamin D levels tested?
If you are female, younger, spend limited time outdoors, or live in areas with reduced winter sunlight, getting tested is worthwhile. A blood test can determine if you have deficiency or insufficiency requiring dietary changes or supplements.
Want to Apply This Research?
- Track your vitamin D blood test results every 3 to 6 months, noting the season and your sun exposure habits. Record dietary sources of vitamin D consumed daily, including fatty fish, fortified milk, and egg consumption.
- Set a goal to spend 15 to 20 minutes outdoors during midday hours at least 3 times per week. Log vitamin D supplement intake if prescribed, and track dietary sources of vitamin D like salmon, mackerel, fortified orange juice, and mushrooms exposed to sunlight.
- Create a seasonal vitamin D tracker that accounts for natural fluctuations in sun exposure. Monitor sun exposure minutes weekly and correlate with dietary vitamin D intake. Schedule reminders for vitamin D testing before winter months when levels typically drop.
This research describes vitamin D status in a specific Brazilian military and civilian population and should not be used for self-diagnosis. Vitamin D levels vary by individual, location, and season. If you suspect vitamin D deficiency, consult with a healthcare provider for blood testing and personalized recommendations. This article is for informational purposes only and does not replace professional medical advice. Always speak with your doctor before starting supplements or making significant dietary changes.
This research translation is published by Gram Research, the science division of Gram, an AI-powered nutrition tracking app.