Vitamin D3, listed as cholecalciferol, is the best-known ingredient on the list, which is why the missing amount stands out.
The NIH Office of Dietary Supplements describes vitamin D as helping the body absorb calcium and supporting bones, and notes roles in muscle and immune function. Cholecalciferol is the D3 form your skin makes in sunlight. Many adults do not get enough through food and sun, which is why it is common in supplements.
Research that links vitamin D to testosterone generally applies to people who are deficient, as our post on zinc and vitamin D explains.
The NIH lists 4,000 IU (100 mcg) a day as the upper intake level for adults. If you also take a multivitamin or a separate vitamin D supplement, you need to know how much HoneyFil adds. Without a per-gummy figure you cannot add it up. A blood test through your doctor is the reliable way to know your own level.