digest
Short Summary
Main recommendation: Take vitamin D3 daily, typically 2,000 to 10,000 international units per day, ideally with a good-quality oil and in partnership with a doctor who checks your vitamin D 25 level. Dr. Berry argues that vitamin D deficiency is very common, that D3 is better absorbed than D2, and that overdose is rare to the point of being a myth.
Key Points
- Dr. Berry says he found that far more than 50% of his patients were vitamin D deficient once he began checking the correct test, the vitamin D 25 level rather than vitamin D 1,25.
- He prefers vitamin D3 over the prescription D2 because D3 is absorbed better and more naturally; he suggests buying D3 over the counter if a doctor prescribes D2.
- He says people living north of a line between LA and Atlanta, or at very northern or southern latitudes, often cannot make enough vitamin D from sunlight and need a supplement.
- He reports no documented cases of vitamin D overdose death or hospitalization in the literature he found, and says he has seen only about three patients with a vitamin D 25 level over 100, which resolved by lowering the dose.
- He cites a study in which people given 4,000 international units of vitamin D daily had a lower waist-to-hip ratio after a few months, though he notes a further study would be needed to prove causation.
Details Worth Noting
- Concrete instructions:
- Ask a doctor to check your vitamin D 25 level (not vitamin D 1,25) with routine lab work, which he suggests once, twice, or up to four times a year.
- Choose vitamin D3, which is sold over the counter at health food stores or pharmacies, rather than D2 as a default.
- Take a daily D3 dose rather than a large weekly or monthly dose, since the body can only absorb a limited amount at a time (he says about 1,200 units a day through the skin).
- Start in the range of roughly 2,000 to 10,000 international units per day, adjusting with your doctor based on lab results.
- Take the D3 with a good-quality oil such as avocado, cod liver, lard, tallow, or olive oil to increase absorption.
- If your level is low, optimize it promptly; if your level is high, back off the dose to bring it back to normal.
- He notes that a 50,000-unit D2 dose taken monthly means most of the month has no active vitamin D in the body, which he considers an unhelpful pattern.
- He acknowledges his overdose claim is based on his reading and clinical experience, inviting anyone who finds contrary studies to send them to him.
- He mentions that he was never taught to supplement or check vitamin D in adults during medical training, and that he was taught (incorrectly, as he later learned) that women do not make vitamin D in breast milk, a point he says he will address in a later video.
Bottom Line
Testing your vitamin D 25 level and, if it is low, using a daily D3 supplement with a healthy oil, guided by a doctor, is the practical takeaway; Dr. Berry considers overdose a minor concern compared with widespread deficiency.
