When is the best time for babies to take vitamin D3?

When is the best time for babies to start taking vitamin D3? It's best to begin after two months of age. Supplementation should ideally continue until at least two years old. If a child shows clear signs of vitamin D3 deficiency, supplementation may be extended to 2.5 or even 3 years under medical supervision. Always use vitamin D3 as directed by a doctor to avoid excessive intake, which could lead to vitamin D3 toxicity. Additionally, ensure daily outdoor sun exposure for about half an hour.