This is The Download, your weekday briefing on the world of technology. We begin with the critical role of vitamin D in our bodies. Many living in the Northern Hemisphere face vitamin D deficiency due to reduced sunlight exposure. Supplementation can be important to maintain optimal health. This article first appeared in The Checkup, MIT Technology Review’s weekly biotech newsletter. To receive it in your inbox every Thursday, sign up here. Recent biotech stories include advancements in organs on chips, the latest company planning for gene-edited babies, and the challenges of creating a cold vaccine. Scientists are also exploring the creation of bodies without sperm or eggs, raising ethical questions, and a retina implant is helping people with vision loss. Next, we journey to Kigali, Rwanda, for Deep Learning Indaba, one of Africa's largest AI and machine learning conferences. The event gathers African researchers and technologists, showcasing their work and fostering collaboration. While many attendees seek opportunities with established tech companies or PhD programs, organizers hope to stimulate local AI innovation and job creation within Africa. This story is from the latest print issue of MIT Technology Review magazine. The must-reads

Google’s new Nano Banana Pro generates convincing propaganda (The Verge)
Taiwan says the US won’t punish it with high chip tariffs (FT)
Mental health support is one of the most dangerous uses for chatbots (WP)
It costs an average of $17,121 to deport one person from the US (Bloomberg)
Grok is telling users that Elon Musk is the world’s greatest lover (Rolling Stone)
Who’s really in charge of US health policy? (Vox)
Inequality is worsening in San Francisco (WP)
Donald Trump is thrusting obscure meme-makers into the mainstream (NYT)
Moss spores survived nine months in space (New Scientist)
Does AI really need a physical shape? (The Atlantic)

Quote of the day “At some point you’ve got to wonder whether the bug is a feature.” —Alexios Mantzarlis, director of the Security, Trust and Safety Initiative at Cornell Tech, ponders xAI and Grok’s proclivity for surfacing Elon Musk-friendly and/or far-right sources, the Washington Post reports. One more thing The AI lab waging a guerrilla war over exploitative AI. Ben Zhao, a computer security researcher at the University of Chicago, and his colleagues have built two tools called Glaze and Nightshade that add barely perceptible perturbations to an image’s pixels so that machine-learning models cannot read them properly. Zhao sees the tools as part of a battle to slowly tilt the balance of power from large corporations back to individual creators. We can still have nice things

If you’re ever tempted to try and recreate a Jackson Pollock painting, maybe you’d be best leaving it to the kids.
Scientists have discovered that lions have not one, but two distinct types of roars
The relentless rise of the quarter-zip must be stopped!
Pucker up: here’s a brief history of kissing