Apparently, there are a number of variables, with some populations exceeding 100 through sun exposure.
Highest Vitamin D Levels
• Indigenous populations in Tanzania, such as the Maasai and Hadzabe, have some of the highest recorded mean serum 25(OH)D levels, with studies reporting averages over 106 nmol/L, and pregnant Maasai women averaging up to 138.5 nmol/L.
• Vietnam has mean levels around 92 nmol/L for men and 75 nmol/L for women, which are also among the highest globally outside of Africa.
• Populations in the Gambia also show higher-than-global-average vitamin D levels, with mean values around 91 nmol/L in women aged 45–80.
Key Factors Influencing High Levels
• Sunlight exposure is the main reason, as these populations often live near the equator with abundant year-round sun and engage in outdoor lifestyles.
• Minimal clothing restrictions allow for more skin exposure to ultraviolet B, promoting natural vitamin D synthesis.
• Diets with some fish and non-industrialized habits may also support higher vitamin D status in some Asian populations, like Japan and Vietnam
Indigenous populations in Tanzania, such as the Maasai and Hadzabe, have some of the highest recorded mean serum 25(OH)D levels, with studies reporting averages over 106 nmol/L, and pregnant Maasai women averaging up to 138.5 nmol/L.
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Note that 138.5 nmol/L is 55.5 ng/ml. Source:
https://www.grassrootshealth.net/project/ng-ml-nmol-l-converter/