Vitamin-D sun time API

Estimates minutes of midday sun needed for a target vitamin-D dose given UV index and Fitzpatrick skin type, via a standard erythemal-dose conversion. Answers 'How long in UVI 8 sun to make 1000 IU vitamin D?', 'How much sun does a darker-skinned person need?'.

Price$0.04per request

MethodPOST

Route/v1/climate/vitamin-d-exposure

StatusLive

MIME typeapplication/json

Rate limit120/minute

Cache0s public

vitamin-dsun-exposureuv-indexfitzpatrickhealtherythemalsupplementationsunlight

API URLhttps://x402.hexl.dev/v1/climate/vitamin-d-exposure

Integration docs

Example request

{
  "uvIndex": 8,
  "skinType": 3,
  "targetIu": 1000
}

Example response

{
  "exposureMinutes": 10.8,
  "uvIndex": 8,
  "skinType": 3,
  "targetIu": 1000,
  "standardErythemalDosesNeeded": 1.3,
  "interpretation": "~11 min midday sun on ~25% skin to make 1000 IU vitamin D (skin type 3, UVI 8).",
  "formula": "time = (100 J/m² per SED / (UVI×0.025)) × (targetIU/1000 × skinFactor); 1 SED≈1000 IU for type II"
}

Input schema

{
  "type": "object",
  "required": [
    "uvIndex"
  ],
  "properties": {
    "uvIndex": {
      "type": "number",
      "description": "UV index",
      "examples": [
        8
      ]
    },
    "skinType": {
      "type": "number",
      "description": "Fitzpatrick skin type 1-6 (default 2)",
      "examples": [
        3
      ]
    },
    "targetIu": {
      "type": "number",
      "description": "Target vitamin-D dose in IU (default 1000)",
      "examples": [
        1000
      ]
    }
  }
}

Output schema

{
  "type": "object",
  "additionalProperties": true
}