Table 2.

The supplementation and treatment dosage of vitamin D for vitamin D deficiency and prevention and treatment of SARS-CoV-2 infection. Compiled from the Endocrine Society Guidelines [133].

Ages	Supplementation doses	Upper tolerable dose	Treatment and preventive doses
0–1 year	400–1000 IU/d. To achieve a serum level of 25(OH)D above 30 ng/mL need at least 1000 IU/d.	2000 IU/d	2000 IU/d or 50,000 IU/wkly for 6 wk to achieve a serum level of 25(OH)D above 30 ng/mL, followed by 400–1000 IU/d.
1–18 years	600–1000 IU/d. To achieve a serum level of 25(OH)D above 30 ng/mL need at least 1000 IU/d.	4000 IU/d	2000 IU/d or 50,000 IU/weekly for 6 wk to achieve a serum level of 25(OH)D above 30 ng/mL, followed by 600–1000 IU/d.
19 –50 years	600–1500 IU/d. To achieve a serum level of 25(OH)D above 30 ng/mL need at least 1500 –2000 IU/d.	4000 IU/d	6000 IU/d or 50,000 IU/weekly for 6 wk to achieve a serum level of 25(OH)D above 30 ng/mL, followed by 1500–2000 IU/d.
50 –70 years	800–2000 IU/d. To achieve a serum level of 25(OH)D above 30 ng/mL need at least 1500 –2000 IU/d.	10,000 IU/d	6000 IU/d or 50,000 IU/weekly for 8 wk to achieve a serum level of 25(OH)D above 30 ng/mL, followed by 1500–2000 IU/d.
70 + years	1000–2000 IU/d. To achieve a serum level of 25(OH)D above 30 ng/mL need at least 1500 –2000 IU/d.	10,000 IU/d	6000 IU/d or 50,000 IU/weekly for 8 wk to achieve a serum level of 25(OH)D above 30 ng/mL, followed by 1500–2000 IU/d.
Pregnant and lactating women	1500–2500 IU/d. To achieve a serum level of 25(OH)D above 30 ng/mL need at least 1500 –2000 IU/d.	10,000 IU/d	6000 IU/d or 50,000 IU/weekly for 8 wk to achieve a serum level of 25(OH)D above 30 ng/mL, followed by 1500–2000 IU/d.
Obese and anticonvulsant medications	To achieve a serum level of 25(OH)D above 30 ng/mL need at least two to three times more vitamin D for their age group.	–	2 to 3 times more for their age group to achieve a serum level of 25(OH)D above 30 ng/mL, followed by maintenance therapy of 3000–6000 IU/d.