Vitamin D

Ever since doing Snake Oil visualization, I’ve become a little obsessed with optimising my diet. Hey – what else is there to do on a winter evening? Strange thing. Vitamin D keeps popping up in all kinds of research. Evidence seems to be growing for its extensive potential role in health, cancer prevention and even mental health and mood.


Deficiency may even be a contributing factor for the greater prevalence of heart disease and diabetes among African-Americans (dark-skinned peoples have much more difficulty synthesising vitamin D from sunlight). Nearly 100% African Americans could have insufficient Vitamin D, according to some studies. Nearly 1 in 3 could be severely deficient.

I got curious. And inevitably that curiosity spawned a yomming great infographic.

» See the data



UPDATE: 1st Dec. The US Institute of Medicine have released an equally yomming report on Vitamin D. (Story in NY Times | Original PDF report) It does a lot of cross- and meta-analysis on the various studies out there. Some findings contradict what I’ve visualized here. So I’ve folded in the new info and adapted the visuals. You can see a detailed summary in the Change Log. The headlines are: 

  • Evidence for health benefits beyond bone health are “inconsistent & conflicting” – I’ve changed wording
  • Blood levels that count as ‘insufficient’ vitamin D are disputed and unstandardized – I’ve added a note
  • The Recommended Daily Allowance has been boosted to 600 IU, from 200 IUs – I’ve added this

Everything else seems to stand up! I’ve updated the data spreadsheet too.

(The report doesn’t mention latitudes or UVB exposure. So I’m sticking to my 1000IUs vegicaps a day during the winter)

If you find any other research, please send it over or post below.