A major study following over 91,000 Korean adults for nearly 6 years found that eating more vitamin C-rich foods doesn’t protect against depression. Researchers tracked people’s diets and mood symptoms, expecting to find that those eating the most vitamin C would have fewer depression symptoms. Surprisingly, they found no difference in depression risk between people who ate the least and most vitamin C. Even more unexpected, people taking vitamin supplements had slightly higher rates of depression symptoms, though this increase was very small.

The Quick Take

  • What they studied: Whether eating more vitamin C from foods like oranges and vegetables protects against developing depression symptoms
  • Who participated: Over 91,000 Korean adults who were followed for about 6 years through regular health check-ups
  • Key finding: People who ate the most vitamin C had the same depression risk as those who ate the least - no protective effect was found
  • What it means for you: Don’t rely on vitamin C alone for mood support, but keep eating fruits and vegetables for overall health benefits

The Research Details

This was a large observational study that followed people over time to see who developed depression symptoms. Researchers used food questionnaires to measure how much vitamin C people ate from their regular diet, then divided participants into four groups from lowest to highest intake. They used a standard depression screening tool called the CES-D scale to identify when people developed depression symptoms during follow-up visits.

Following people over nearly 6 years allows researchers to see if vitamin C intake actually prevents depression from developing, rather than just comparing people at one point in time. The large sample size of over 91,000 people makes the results more reliable than smaller studies.

This study’s strengths include its large size, long follow-up period, and use of validated tools for measuring both diet and depression. However, it only included Korean adults, so results may not apply to other populations.

What the Results Show

The main finding was clear: people in the highest vitamin C intake group had virtually identical depression risk compared to those in the lowest group. The researchers found no meaningful difference across any of the four intake levels they studied. This held true when they looked at men and women separately, and when they accounted for factors like age, income, and other health behaviors. The results were consistent regardless of how physically active people were.

Surprisingly, people taking vitamin supplements (not just vitamin C, but any vitamins) had an 8% higher risk of developing depression symptoms. This small increase was seen in both men and women. The researchers noted this could be because people who already feel unwell are more likely to take supplements, rather than supplements causing depression.

Previous smaller studies had suggested vitamin C might help with mood because of its antioxidant properties, but this large, long-term study contradicts those earlier findings. This research provides much stronger evidence because of its size and design.

The study only included Korean adults, so results may not apply to other ethnic groups. Researchers relied on people reporting their own food intake, which isn’t always perfectly accurate. They also couldn’t account for all possible factors that might influence both vitamin C intake and depression risk.

The Bottom Line

Focus on overall healthy eating patterns rather than single nutrients for mental health. Continue eating vitamin C-rich foods like citrus fruits and vegetables for their many health benefits, but don’t expect them to prevent depression on their own. If you’re concerned about depression, talk to a healthcare provider about proven treatments.

Anyone hoping vitamin C supplements or foods might help prevent depression should know this approach lacks strong evidence. People already taking vitamin supplements shouldn’t panic about the small increased risk found, but should discuss with their doctor whether supplements are necessary.

This study followed people for 6 years, so if vitamin C had protective effects, they would likely have been seen within this timeframe.

Want to Apply This Research?

  • Track your daily servings of fruits and vegetables rather than focusing specifically on vitamin C content
  • Focus on building overall healthy eating patterns with plenty of colorful produce, rather than targeting single nutrients for mood benefits
  • Monitor your mood alongside your overall diet quality, physical activity, and sleep patterns to identify what truly impacts your mental wellbeing

This information is for educational purposes only and should not replace professional medical advice. If you’re experiencing depression symptoms, consult with a healthcare provider for proper evaluation and treatment options.