D Fetcher

Calculate vitamin D synthesis at a given location and time. Returns sun position, UV index, IU/min, minutes to reach the target dose, MED (sunburn threshold), the peak window, and optional 15-min day / monthly year curves. UV index uses a live satellite-driven forecast where available, with a clear-sky fallback.

Turn a place name, postal code, or "code, CC" string into { lat, lon, label }. Auto-detects US/CA/GB/NL/JP/BR postal patterns; ambiguous digit-only codes default to US unless the caller appends a country code (e.g. "10115, DE"). Falls back to Open-Meteo place-name search for everything else.

Returns the six Fitzpatrick skin types with sun-reactivity behavior and descriptive ancestry hints. Call this when the user's skin type is unknown so you can pick the closest match before calling calculate.