Few countries on earth get more direct, overhead sun than Kenya. Yet hospital studies from Nairobi to Kenyatta National Hospital keep finding the same pattern: a meaningful share of people test low on vitamin D anyway.
Kenya is one of a handful of countries the equator physically runs through — splitting it almost exactly between the northern and southern hemispheres. That's not a figure of speech, it's latitude. Here's how close some of Kenya's biggest towns sit to it.
| 0.02° N | Nanyuki — the equator line itself runs through town |
| 0.09° S | Kisumu — Lake Victoria region |
| 0.30° S | Nakuru — Rift Valley |
| 0.51° N | Eldoret — North Rift |
| 1.29° S | Nairobi — the capital |
| 4.04° S | Mombasa — the coast |
Different hospitals, different groups of people, different years — each one found a meaningful share of Kenyans testing below sufficient vitamin D levels. Full studies are linked below if you'd like to read them yourself.
Your body only makes vitamin D when UVB rays hit bare skin directly. Kenya has no shortage of UVB — but daily life, geography and climate are all very good at getting between you and it.
Ordinary window glass filters out the UVB wavelength your skin needs — so a bright office with a view of the sun does nothing for your levels.
Time spent in cars, matatus, buses and covered walkways adds up. A long commute can mean a whole working day passes with only minutes of direct, unfiltered sun on the skin.
Both are sensible for skin health — and both measurably reduce how much vitamin D your skin can produce at the same time.
Melanin is your skin's built-in defence against UV damage. That same protection means it takes somewhat more direct sun time to produce the same amount of vitamin D — worth knowing, not worth worrying about.
Kenya's climate isn't uniformly sunny year-round. Highland towns in particular see real cloud cover during the long and short rains, cutting UVB even at midday.
The UVB your skin needs is strongest roughly between 10am and 3pm. Early morning or late afternoon sun feels pleasant but contributes very little.
A simple blood test is the only way to know. From there, your pharmacist can tell you where Core D3 fits.