Taking only 1000 IU of vitamin D only when you don’t get enough sun is very likely to be insufficient. Due to wearing clothes and spending most time indoors even Brazilians are highly deficient in vitamin D.
A study I remember from PubMed but currently can’t find among the flood of vitamin D related studies concluded that 3000 IU per day is a likely average recommendation for adult males. Also, because the response to supplementation varies greatly from person to person the most advisable approach is regular (~ 3 per year) blood testing coupled with adjustments of dosage. For example some people can get to 50 ng/ml blood 25(OH)D levels by taking 2000IU, while others need 7000IU to reach the same levels.
The minimum recommended blood level is usually 50 ng/ml which is as of now well established by evidence but some say that 60-80 ng/ml is still completely safe and might do some additional benefits, so it might be a better target. I personally take 5000 IU per day regardless of which season it is and I hover around 65 ng/ml.
Regarding vitamin D:
Taking only 1000 IU of vitamin D only when you don’t get enough sun is very likely to be insufficient. Due to wearing clothes and spending most time indoors even Brazilians are highly deficient in vitamin D.
A study I remember from PubMed but currently can’t find among the flood of vitamin D related studies concluded that 3000 IU per day is a likely average recommendation for adult males. Also, because the response to supplementation varies greatly from person to person the most advisable approach is regular (~ 3 per year) blood testing coupled with adjustments of dosage. For example some people can get to 50 ng/ml blood 25(OH)D levels by taking 2000IU, while others need 7000IU to reach the same levels.
The minimum recommended blood level is usually 50 ng/ml which is as of now well established by evidence but some say that 60-80 ng/ml is still completely safe and might do some additional benefits, so it might be a better target. I personally take 5000 IU per day regardless of which season it is and I hover around 65 ng/ml.
The Vitamin D Council is a decent source of additional information.
Also, see this great chart for a summary on several risks associated with low vit D levels. It’s a bit dated now but it’s still striking.