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Short Summary
Main recommendation: Dr. Eric Westman says he has never prescribed vitamin D and does not recommend routine vitamin D supplementation for healthy people, because there are few randomized controlled trials showing that supplementation improves outcomes. He instead prioritizes real-food nutrition, and says anyone who supplements should get a blood test and avoid toxicity. The video he reacts to, by Dr. Stephen Ebert, argues vitamin D is the most common deficiency and a biomarker of chronic disease and frailty.
Key Points
- Ebert's central claim, as summarized by Westman, is that vitamin D is the most common deficiency worldwide and that blood levels correlate with overall health and frailty.
- Westman stresses that a correlation between blood level and outcome does not show that raising the level with supplements helps; prospective randomized trials are needed.
- Vitamin D has a classic role (calcium and phosphorus absorption, bone hardening, rickets prevention) and non-classic roles in immune regulation, inflammation, and neurogenesis.
- Westman says the strongest evidence for supplementation is in severe deficiency with bone loss or parathyroid disease, where it probably reduces fracture recurrence.
- Westman notes vitamin D is fat-soluble, so excess can accumulate and cause toxicity, unlike water-soluble vitamins that are excreted.
Details Worth Noting
- Concrete instructions:
- Get a blood test for vitamin D before supplementing, and recheck it during supplementation; Westman says insisting on the test at your next blood work is advisable.
- Blood test units: below 20 ng/dL (50 nmol/L) is deficient, 30 ng/dL (75 nmol/L) is insufficient, and functional medicine practitioners typically set the lower limit at 50 ng/dL. Multiply ng/dL by 2.5 to get nmol/L.
- Westman relays Dr. Ebert's cited optimal range of roughly 50 to 80 ng/dL (about 125 to 200 nmol/L), while expressing doubt this range is proven optimal.
- Above 100 ng/dL (250 nmol/L) is a reason to back off; above 150 ng/dL (375 nmol/L) is vitamin D toxicity.
- Dose guidance mentioned: standard guidelines suggest at least 600 IU per day (800 IU if over about 60), with 2,000 IU cited as the guideline maximum. Westman says many clinic patients need about 5,000 IU, some on 10,000 IU for a month or two if very deficient, but 10,000 IU long-term risks toxicity.
- Westman's own clinic approach: prioritize food (meat, poultry, fish, eggs) and a low-carb, real-food diet first; he sometimes suggests a multivitamin during weight loss if intake is low.
- Westman says he refers severely deficient symptomatic patients to endocrinology colleagues rather than prescribing himself.
- He notes the American College of Physicians and US Preventive Services Task Force guidelines are conservative and he generally waits for their recommendations to change before adopting new practices.
- Westman does not present this as professional advice for individuals; he describes his own clinical practice and views.
Bottom Line
Westman's view is that vitamin D's benefits are plausible but unproven as a supplement for healthy people, so the safer priorities are good nutrition and blood-test-guided dosing if supplementing, with toxicity avoided.
