Researchers studied whether a supplement called N-acetylcysteine (NAC) could help restore vitamin D levels in people recovering from alcohol addiction. They tracked 47 men in treatment for eight weeks, comparing those who took NAC to those who took a placebo. The surprising finding: neither the NAC nor simply stopping drinking improved vitamin D levels. Nearly half of the patients started with dangerously low vitamin D, and this didn’t change much even after two months of recovery. This suggests that people recovering from alcohol use disorder may need extra vitamin D support beyond just quitting drinking.

The Quick Take

  • What they studied: Whether a medication called NAC could help restore vitamin D levels in people recovering from alcohol addiction, and whether simply stopping drinking would naturally bring vitamin D back to normal
  • Who participated: 47 adult men being treated for alcohol use disorder in a hospital setting. About half received NAC pills twice daily for eight weeks, while the other half received fake pills (placebo)
  • Key finding: Vitamin D levels stayed low in both groups. At the start, 45% had dangerously low vitamin D and 22% had moderately low levels. After eight weeks, 43% still had dangerously low levels and 40% had moderately low levels. The NAC medication made no difference compared to placebo
  • What it means for you: If you’re recovering from alcohol addiction, don’t assume your vitamin D will naturally bounce back just by stopping drinking. You may need to actively work with your doctor to restore vitamin D levels through supplements or other interventions, rather than waiting for it to improve on its own

The Research Details

This was a rigorous type of study called a randomized, double-blind, placebo-controlled trial. Researchers randomly assigned 47 men recovering from alcohol addiction into two groups: one group received NAC (a medication thought to help with recovery), and the other received placebo pills that looked identical but contained no active ingredient. Neither the patients nor the researchers knew who got the real medication until the study ended. This design helps eliminate bias and shows whether the medication actually works.

The study lasted eight weeks, with blood tests taken at the beginning and end to measure vitamin D levels and other markers of liver and kidney health. The researchers used advanced statistical methods to analyze whether NAC, time, or the combination of both affected vitamin D levels.

This research approach is important because it directly tests whether NAC can fix a specific problem (low vitamin D) in people recovering from alcohol addiction. By using a placebo control group, researchers could see whether any improvements came from the medication itself or just from stopping drinking. The double-blind design prevents expectations from influencing results.

This study has several strengths: it used a rigorous randomized design, included a placebo control group, and measured objective blood markers rather than relying on patient reports. However, the study only included men, so results may not apply equally to women. The sample size of 47 is relatively small, which means the findings are less definitive than a larger study would be. The study was published in a peer-reviewed medical journal, meaning other experts reviewed it before publication.

What the Results Show

The main finding was clear: NAC did not improve vitamin D levels compared to placebo. Both groups showed similar patterns—vitamin D stayed low throughout the eight-week study period. At the beginning, nearly half of all patients (45%) had vitamin D deficiency (dangerously low levels), and about one-fifth (22%) had vitamin D insufficiency (moderately low levels). After eight weeks of treatment, the numbers barely changed: 43% still had deficiency and 40% had insufficiency.

Interestingly, the pattern shifted slightly—some people moved from deficiency to insufficiency rather than improving all the way to normal—but overall vitamin D levels did not meaningfully improve. The NAC medication showed no statistical advantage over placebo in helping vitamin D recover.

The study also measured liver and kidney function, as well as glutathione (a natural protective substance in the body). While the abstract doesn’t detail these secondary findings, the fact that NAC didn’t improve vitamin D suggests that the medication’s liver-protective effects weren’t enough to restore vitamin D metabolism to normal levels. This indicates that vitamin D deficiency in people with alcohol use disorder may be a stubborn problem requiring direct intervention.

Previous research has shown that people with alcohol addiction often have low vitamin D levels because alcohol damages the liver, which is where vitamin D is processed and activated. Researchers hoped that NAC, which is known to protect the liver, might help restore vitamin D levels. However, this study suggests that liver protection alone isn’t sufficient to fix vitamin D deficiency. This finding adds important nuance to our understanding—stopping drinking and protecting the liver may not be enough; vitamin D may need to be directly supplemented.

The study only included men, so we don’t know if results would be the same for women. The sample size of 47 is relatively small, which means the study had limited power to detect smaller effects. The study lasted only eight weeks, so we don’t know what happens over longer recovery periods. The study didn’t measure sun exposure or dietary vitamin D intake, which could affect results. Additionally, the study didn’t examine whether vitamin D supplementation would actually help these patients, only whether NAC would help.

The Bottom Line

People recovering from alcohol addiction should discuss vitamin D testing and supplementation with their healthcare provider. The evidence suggests that simply stopping drinking won’t restore vitamin D levels on its own. Vitamin D supplements, increased sun exposure, or dietary changes may be necessary. This recommendation has moderate confidence because while this study shows NAC doesn’t help, it doesn’t prove that direct vitamin D supplementation would work—though that’s a reasonable next step to discuss with a doctor.

This research is most relevant to people recovering from alcohol addiction, their healthcare providers, and addiction treatment programs. Anyone in recovery should ask their doctor about vitamin D screening and supplementation. This is less relevant to people without alcohol use disorder, though the general principle that vitamin D deficiency requires active treatment applies broadly.

Based on this study, vitamin D levels didn’t improve over eight weeks of abstinence and NAC treatment. If you’re in recovery and start vitamin D supplementation, it typically takes 4-8 weeks to see meaningful improvements in blood levels, though you may feel benefits (like improved mood and energy) sooner. Discuss realistic timelines with your healthcare provider.

Want to Apply This Research?

  • Track vitamin D supplementation daily (dose and type) and log any symptoms associated with vitamin D deficiency like fatigue, mood changes, or muscle weakness. Set reminders for vitamin D supplement intake and schedule follow-up blood tests every 8-12 weeks to monitor improvement
  • If you’re in recovery from alcohol addiction, work with your doctor to establish a vitamin D supplementation routine. This might include daily supplements, increased time in sunlight (with sun protection), or dietary changes like eating more fatty fish and fortified dairy. Log your supplement intake in the app to build consistency
  • Create a long-term tracking system that records vitamin D supplement doses, any dietary sources of vitamin D, sun exposure time, and symptoms. Schedule quarterly blood tests to monitor vitamin D levels and adjust supplementation as needed. Track mood, energy, and overall wellness to correlate with vitamin D improvements

This research suggests that vitamin D deficiency is common in people with alcohol use disorder and doesn’t improve automatically with abstinence or NAC treatment. However, this study does not prove that vitamin D supplementation will help—only that NAC alone doesn’t. If you’re recovering from alcohol addiction or have concerns about vitamin D levels, consult with your healthcare provider before starting any supplements. This information is educational and should not replace professional medical advice. Always work with your doctor to develop a personalized treatment plan for alcohol use disorder and any nutritional deficiencies.