Vitamin D for Morning Fatigue

Vitamin D improves fatigue in some trials of deficient participants but shows nothing in replete populations. Effect sizes are small and inconsistent.

Overview

Vitamin D improves fatigue in some trials of deficient participants but shows nothing in replete populations. Effect sizes are small and inconsistent.

Verdict

Mixed evidence

Worth correcting if deficient, but do not expect it to fix unrefreshing sleep or sleep apnoea.

How It Works

Vitamin D receptors are present in skeletal muscle and the central nervous system; severe deficiency causes proximal myopathy and bone pain that are experienced as fatigue.

Dosing & Protocol

Typical dose

Recommended dose: 1000-2000 IU daily if 25(OH)D is below 50 nmol/L
Expected timeframe: 8-12 weeks for repletion and any symptomatic change.

Protocol

form: D3
notes: Daily dosing outperforms bolus
duration: Retest at 3 months
starting dose: 1000-2000 IU daily

Evidence

What the studies say

Small randomised trials in deficient adults, including a 2016 trial in vitamin D deficient patients with fatigue, reported improved fatigue scores after repletion. Larger trials in unselected populations, including VITAL substudies, show no effect on wellbeing or energy. The pattern mirrors the respiratory infection literature: benefit concentrated in deficiency, absent in sufficiency. Fatigue attributed to vitamin D is frequently caused by sleep apnoea or iron deficiency instead, and both are more productive to investigate.

Effects of vitamin D on patients with fibromyalgia syndrome: a randomized placebo-controlled trial

Score: 6/10

2014

rct

n=30

Wepner F

Optimization of calcifediol levels in FMS had a positive effect on the perception of pain.

View source

Safety

Caveats

High-dose intermittent regimens have been associated with increased falls in older adults. Avoid doses above 4000 IU daily without monitoring.

Less likely to help if

People with a sufficient baseline level, and those whose fatigue is driven by apnoea or circadian misalignment.

Medical Disclaimer

The information provided on this website is for educational and informational purposes only and is not intended as a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition or before starting any supplement regimen.

Individual results may vary. The statements on this website have not been evaluated by the Food and Drug Administration. Products and information are not intended to diagnose, treat, cure, or prevent any disease.