Supplements Guidelines For Adults

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Vitamin D, Zinc, And Other Supplements

Following Dr. Michael Cohen‘s conversation with Dr. John Campbell on YouTube about Vitamin D and other supplements, we were contacted by many asking for recommendations. We are happy to provide here guidelines for adults (guidelines for children will be posted at a later date) for supplements which may be helpful in reducing the severity of viral infections including COVID-19.

At Tel Aviv Doctor we offer a wide range of medical services including online consultations and case management for complex cases. Please get in touch for more information or set an appointment.

Vitamin D3 for adults

  • 2000-4000 units daily with an aim of reaching a vitamin D 25 OH level (25-hydroxy vitamin D) of 50-100 ng/ml
  • NOTE: Some people may require as much as 8000 units or more per day

Vitamin K2

  • 100-200 mcg daily to minimise problems of using long term vitamin D (4000 units and above)
  • NOTE : if on a blood thinner such as warfarin/coumadin you need to avoid this vitamin and discuss with the prescribing doctor and then keep vitamin D to a limit of 4000 units daily and be monitored (blood test level of vitamin D).


  • 25 mg once daily during the pandemic.


  • It is very difficult to test for magnesium – it is a good idea to take magnesium while on vitamin D3
  • There are various formulations: Magnesium citrate 300 mg daily at night time is a reasonable choice.

Always consult your own doctor before taking any medication or supplements. It is not possible to give generalised medical guidelines, for example vitamin K2 may interfere with some anticoagulant medications, so you should see your doctor for individualises advice.

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