It depends - ancient ancestors had a lot of different lifestyles. For example, Soranus of Ephesus reported deformations in the bones of children as early as the 100 CE.
However, this is I think what you are trying to get at:
One particular epidemiological study stands out as a guide for what typical 25-(OH)D levels might have been be for our earliest ancestors.
Luxwolda et al. studied populations of pastoral Masai and hunter-gatherer Hadzabe, sampling their blood for 25-(OH)D levels and taking note of their daily habits in reference to UV exposure.
The mean 25-(OH)D concentration in these populations was 115 nmol/L, with a range of 58 nmol/L to 171 nmol/L.
This study provides a general framework for the expected 25-(OH)D level of active, healthy humans working outdoors at a low (< 5 degrees) latitude. Humans have modified their living conditions greatly from this model of ancestral life, leading to reduced exposure to UV radiation.
However, this is I think what you are trying to get at:
One particular epidemiological study stands out as a guide for what typical 25-(OH)D levels might have been be for our earliest ancestors.
Luxwolda et al. studied populations of pastoral Masai and hunter-gatherer Hadzabe, sampling their blood for 25-(OH)D levels and taking note of their daily habits in reference to UV exposure.
The mean 25-(OH)D concentration in these populations was 115 nmol/L, with a range of 58 nmol/L to 171 nmol/L.
This study provides a general framework for the expected 25-(OH)D level of active, healthy humans working outdoors at a low (< 5 degrees) latitude. Humans have modified their living conditions greatly from this model of ancestral life, leading to reduced exposure to UV radiation.