Vitamin D is worth a shot for SAD

Vitamin D supplements can help with seasonal affective disorder in late winter, but they’re not a magic bullet.

The logic is solid: SAD is linked to less sunlight, your body makes vitamin D from sunlight, and vitamin D plays a role in mood regulation. So yes, taking a supplement (around 1000–2000 IU daily, but don’t overdo it) is a reasonable move, especially if you’re already low. Some studies show a small benefit, others don’t, but it’s cheap and low risk.

Diet-wise, you’re better off focusing on complex carbs (oatmeal, whole grains) to help with serotonin production, and omega-3s (fatty fish, walnuts) for general brain health. But no specific “SAD diet” is going to replace the gold standard treatment, which is bright light therapy. That’s 10,000 lux for 20–30 minutes in the morning.

Bottom line: Vitamin D is a nice adjunct, not a replacement for proper light exposure. If you’re dragging in February, try the light box first, then add vitamin D as backup.