From the Research
Vitamin D supplements do not typically cause blood thinning, and individuals can generally take them without concern for interactions with blood clotting mechanisms. The primary function of vitamin D is in calcium absorption and bone health, not in blood coagulation pathways 1. However, it's essential to note that extremely high doses of vitamin D (above 10,000 IU daily for extended periods) may indirectly affect blood calcium levels, which could theoretically impact clotting in some individuals. For most people taking standard vitamin D supplements (600-4,000 IU daily), there is no significant risk of blood thinning effects. Some studies suggest that vitamin D levels may have an impact on bleeding risk in patients taking warfarin, with higher vitamin D levels potentially associated with an increased risk of major bleeding 1. However, this does not necessarily mean that vitamin D supplements cause blood thinning. If you're taking blood thinners like warfarin, apixaban, or rivaroxaban, you can generally take vitamin D supplements without concern for interactions, but it's always best to inform your healthcare provider about all supplements you're taking. People with certain medical conditions like hyperparathyroidism should consult their doctor before taking vitamin D supplements as it could affect calcium metabolism. In terms of dosage, a daily dose of 1,000-1,200 mg calcium and 800 IU vitamin D is recommended in elderly or institutionalized people, patients with established osteoporosis, and individuals on glucocorticoids 2. It's also important to consider that prolonged consumption of vitamin D supplementation may induce hypercalcemia, hypercalciuria, and hyperphosphatemia, which are considered to be the initial signs of vitamin D intoxication 3. Overall, while vitamin D supplements are not typically associated with blood thinning, it's crucial to be aware of the potential risks and interactions, especially in individuals with certain medical conditions or those taking blood thinners.