Is It Stress, or Is It Your B-Complex?

Low energy, mood swings, brain fog, could your body be asking for B vitamins?

Stress and exhaustion have become so common, they’re almost expected. But if you’re feeling mentally drained, physically flat, or unusually irritable, it’s worth asking whether your symptoms are really from burnout or from a nutrient your body is missing.

As a doctor, I’ve found that many of my patients don’t realise how essential B vitamins are to daily functioning. They’re often depleted during times of stress, and many women aren’t getting enough of the right forms.

What You Need to Know

B vitamins are a group of eight nutrients that work together to support energy production, nervous system function, hormone metabolism, brain health, and even detoxification.

Here’s a quick overview:

• B1 (Thiamine): helps turn food into energy and supports brain function.

• B2 (Riboflavin): crucial for energy metabolism and skin health

• B3 (Niacin): involved in DNA repair and mood regulation.

• B5 (Pantothenic Acid): supports adrenal function and hormone synthesis.

• B6 (Pyridoxine): important for neurotransmitters like serotonin and GABA.

• B7 (Biotin): best known for hair and nail support.

• B9 (Folate): essential for methylation, mood, and reproductive health.

• B12 (Cobalamin): needed for nerve function and red blood cell production.

Stress, certain medications (like birth control or antacids), poor absorption, alcohol, and restrictive diets can all reduce B-vitamin levels, especially B12 and folate.

Why It Matters

When B vitamins are low, your body struggles to make energy at the cellular level. That can lead to:

• Fatigue, even after sleeping well.

• Mood swings or low mood.

• Difficulty focusing or retaining information.

• Tingling in hands or feet.

• Poor stress tolerance.

• Menstrual irregularities or hormonal shifts.

In practice, I’ve seen how quickly these symptoms can turn around when the right B-complex is added. But not all supplements are equal, many over-the-counter brands use forms that aren’t well absorbed or tolerated.

What You Can Do

If you’ve been feeling run down, ask your healthcare provider to check vitamin B12 and folate levels. Be sure the lab checks active B12, not just total B12, as the standard test can sometimes be misleading.

If supplementing, look for:

• Methylated forms of B12 (methylcobalamin) and folate (L-5-MTHF or Quatrefolic).

• A full-spectrum B-complex with all eight vitamins in balanced doses.

• Clean formulas without unnecessary fillers or megadoses that can cause side effects.

It’s often best to take B vitamins in the morning, as they can increase alertness and support daytime energy.

Doctor’s Insight

I’ve found that women going through busy, transitional life stages, whether it’s perimenopause, returning to work, or caring for family, are especially vulnerable to B-vitamin depletion. They often push through the exhaustion, thinking it’s “just stress.”

But when we support the underlying biochemistry, their resilience comes back. They sleep better, cope more easily, and feel like themselves again.

Disclaimer:
This article is for informational purposes only and does not constitute medical advice. Please consult your healthcare provider before starting any new supplement.

References:

1. National Institutes of Health: B Vitamins Fact Sheets

2. Harvard Health: Vitamin B12 Deficiency and Brain Function

3. Journal of Clinical Psychiatry (2020): The Role of B Vitamins in Mood and Cognition

4. Mayo Clinic: Folate vs Folic Acid: - What's the Difference?

5. Nutrients (2021): Methylation and Mental Health: Role of B12 and Folate