https://www.youtube.com/watch?v=7zakDUZHSrM

Physical symptoms of vitamin D insufficiency may include aching muscles, painful bones, reduced physical performance, poor sleep, hair loss and slow-healing wounds
You may also experience poor sleep, fatigue, dizziness, increased risk of dementia and depression, increasing weight, recurring infections and reduced cognitive functioning
Vitamin D plays a role in nearly every bodily system, including fighting against viral and bacterial illnesses
The only way to know your serum level is to take a blood test. If you choose to supplement with vitamin D3, it's important to include magnesium and vitamin K2 MK-7 to achieve optimal levels and improve your cognitive and cardiovascular health