A complete safety, timing, and dosage guide for combining St. John's Wort with Vitamin D (D2, D3) — including how the two supplements interact, the best time of day to take each, and which populations should be careful.
Yes, you can take Vitamin D (D2, D3) and St. John's Wort together safely — there is no known negative interaction between them.
Vitamin D and St. John's Wort together are considered safe. St. John's Wort does not meaningfully affect vitamin D absorption or metabolism, so you can continue both without concern.
Vitamin D is fat-soluble and is absorbed in the small intestine with dietary fat. It is then hydroxylated in the liver by CYP2R1 to 25-hydroxyvitamin D, and later in the kidney by CYP27B1 to the active form calcitriol. St. John's Wort is known to induce cytochrome P450 enzymes, especially CYP3A4, and P-glycoprotein, which can speed up metabolism of many drugs. However, vitamin D's primary metabolic enzymes (CYP2R1, CYP27B1, CYP24A1) are not significantly affected by St. John's Wort, and the contribution of CYP3A4 to vitamin D metabolism is minor. Additionally, there is no competition for absorption because vitamin D requires bile and fat for uptake, whereas St. John's Wort's active compounds like hypericin and hyperforin are absorbed through different mechanisms. Therefore, the two supplements do not interfere with each other in the body.
Take both vitamin D and St. John's Wort once daily with your largest meal, preferably one containing avocado, nuts, olive oil, or eggs. There is no need to separate them by any specific time interval. For vitamin D, the D3 form in a softgel or liquid drop is well absorbed when taken with fat. St. John's Wort can be taken right alongside it; if you forget a dose, skip it and resume the next day. Periodically check your vitamin D levels with your healthcare provider to ensure you are in the optimal range.
Vitamin D3 (cholecalciferol) is generally more effective than vitamin D2 (ergocalciferol) at raising and maintaining serum 25(OH)D levels, but the lack of interaction with St. John's Wort applies to both forms. St. John's Wort is often sold as a standardized extract (e.g., 0.3% hypericin), but the specific extract or product form does not change the interaction profile. Choose high-quality products from reputable brands to ensure consistent dosing.
Vitamin D is commonly found in bone-health stacks with calcium and vitamin K2, while St. John's Wort is typically used alone for mood support, so these two rarely appear together in commercial supplement products.
Yes, you can take them together. There is no known interaction that affects absorption or effectiveness. I recommend taking them with a meal for best tolerance.
Yes, it is safe for most people. St. John's Wort does not change how your body uses vitamin D. Just be aware that St. John's Wort can interact with other medications, so confirm with your provider.
You do not need to wait at all. Because they do not interact, you can take them at the same time.
No, they do not compete. Vitamin D is absorbed with dietary fat, while St. John's Wort is absorbed through different pathways, so there is no conflict.
Most adults can take them together safely. However, pregnant or breastfeeding women should avoid St. John's Wort, and anyone taking medications that interact with St. John's Wort should consult their doctor before combining them.
I recommend taking Vitamin D with a meal that contains fat to improve absorption. St. John's Wort can also be taken with food to reduce stomach upset, so taking both at breakfast is a simple approach.
Reviewed by Caroline M. on April 15, 2026 for accuracy against the sources listed above. This page is educational and is not a substitute for professional medical advice.
The matrix has 86 supplements and 7310 pairwise interactions. Click any cell to see the full breakdown.