#1) If you got a BATHING SUIT quality tan yesterday, then you don't need to take Vitamin D today.
This means: 30 minutes of exposure between 10 am & 2 pm wearing –>
Ladies – 2 a piece suit Boys – this means trunks
NO SUNSCREEN during this 30 minute exposure.
Remember – Sunburn = BAD Sun TAN = GOOD
#2) Take enough Vitamin D daily to get your blood level between 50 and 100 ng/ml.
MOST adults can safely start at 5000 IU daily of Vit D.
After 2 to 3 months, get a blood level checked. This can be done at your Doctor's office, or, a test kit can be sent to you in the mail.
If your results come back at, say, 38 ng/ml, after taking 5000 IU / day, it is not unreasonable to up your intake to 10,000 IU /day – and recheck a level 2 to 3 months later.
As Vit D is a fat soluble Vitamin, its level does NOT change quickly.
If one googles: "Consequences of low Vitamin D levels", the list of consequences is a list of health issues that no one wants any part of! (Dementia, hypertension, cancer, depression…… + many more)