What do vitamins actually do?

Vitamins are micronutrients human bodies need but don't naturally produce

Each vitamin is found in specific portions of a normal human diet and supports normal human functioning in distinct ways. Vitamin A is found in red meat, carrots, and potatoes and supports vision and skin health, while Vitamin D (common in fish and mushrooms) helps absorb calcium. See sources and uses of each vitamin with this chart.

Humans need vitamins, but research is mixed on taking supplements

When an organism needs an organic molecule to survive, but cannot synthesize enough of it itself, that molecule is called a vitamin. Typically, we consume vitamins through food, but many resort to supplements—a common and mostly unregulated practice.

Humans need higher levels of water-soluble vitamins that easily pass through the body

There are two types of vitamins: lipid soluble and water-soluble. Water-soluble vitamins like B vitamins and vitamin C are in the watery parts of fruits and easily pass through the human body before being taken up by the bloodstream or exiting your body. But lipid (fat) soluble vitamins must be absorbed through the intestinal wall, carried by proteins, and then may be stored in the liver and other body parts—meaning there is greater risk of overdosing.

Do you need a multivitamin?

In 2013, several researchers declared multivitamins dead, stating that so-called supplements had no clear benefits and might be harmful. But the science isn't so clear-cut. This article explores the question of who would benefit from...

What does blood do?

Blood's primary purpose is to ferry oxygen and nutrients to cells in need while collecting cell waste and byproducts for removal. It also enables the body's repair and immune systems to traverse our internal landscape to address cell damage or external invaders, such as viruses and parasites. Zooming out from the exact roles of blood's various cells, the fluid connective tissue also assists with maintaining homeostasis via temperature regulation and pH balance.

Vitamins can slow macular degeneration

Research published in 2022 affirmed that vitamin formulations containing vitamins C and E, copper, zinc, lutein, and zeaxanthin—but no beta carotene—can enhance eye health and slow the progression of macular degeneration.

Aging explained with Dr. Nick Golinvaux

Aging is more than wrinkles and gray hair—it’s a gradual decline in cellular function. Over time, DNA damage, telomere shortening, and mitochondrial inefficiency contribute to weaker bones, slower memory, and reduced vitality. While aging is inevitable, regular exercise, quality sleep, and stress management maintain health and extend one’s years.

How does your body turn food into energy?

Cells get energy via a process known as cellular respiration, which involves turning glucose into ATP or adenosine triphosphate. Breaking the phosphate bonds of ATP results in usable energy being released into cells, which can then use that energy to power biological processes. This 10-minute video explains how glucose turns into ATP, giving the body the energy it needs to survive.

Explore what each organelle does within various types of cells

In "Cell Anatomy Viewer," users can explore interactive illustrations of animal, plant, fungal, and bacterial cells. Clicking on an organelle, such as a lysosome, the nucleolus, or the Golgi complex, provides descriptions of its characteristics and functions.

Watch what depression does to the brain

This video explores the neurobiology of depression and why unraveling the complexities of this disease and its etiology will potentially improve treatments. Effective depression treatment, as this video highlights, can eventually make a depressed brain look like a healthy one on brain scans.

A fascinating look at how our DNA is built and replicated

This easy-to-understand 13-minute video dives into the wondrous molecule deoxyribonucleic acid – also known as DNA – and explains how it replicates itself in our cells.

Myokines are molecules that facilitate some of the benefits of exercise

When muscles contract, they release ‘hope molecules’ (myokines) such as IL-6 and irisin. These proteins then travel through the bloodstream to reduce inflammation, improve insulin sensitivity, and even support brain repair. This piece illustrates how movement triggers a systemic healing cascade throughout the human body.

An interactive dive into the immune system

Our bodies are equipped with an incredible system able to fight off invasive pathogens to protect us from illness. The complicated system includes lymph nodes, the spleen, bone marrow, and even the tonsils. But this same system can turn against itself, a condition known as autoimmune disorders. Follow along with this thorough, engaging explainer on the human body's defense system.

Addressing lifestyle factors, which influence inflammation, can cure some chronic diseases

In this video, a physician claims that he reversed a patient's Type 2 diabetes in six weeks by addressing inflammation drivers such as diet. More broadly, he argues that society needs to better consider and address numerous disease factors that are modulated by inflammation, such as stress, sleep, diet, and movement.

What is vaccination? The World Health Org explains

Read up on the basics of vaccinations with this 101 from the World Health Organization, the public health arm of the United Nations.

How do stem cells actually work?

Stem cells are unspecialized cells that can develop into various cell types while also making exact replicas of themselves. This amazing ability has made stem cells a candidate to treat a wide variety of diseases and conditions—though the vast majority of potential therapies remain in the research stage.

What do investment bankers actually do?

Investment bankers organize large financial transactions at a high level. But what does that look like day to day? A video breaks down the specifics about the transactions and deals investment bankers work on, and which members of an investment banking team have eyes on each project.

The chemistry of ancient tacos

This 16-minute podcast explores the chemistry of Mesoamerica's corn tortillas, which involve a 3,500-year-old chemical process called nixtamalization that releases vitamins, including niacin, one of the essential B vitamins. This process also makes the tortillas softer and more delicious. Corn tortillas were a staple in Mesoamerica, and the archaeologist interviewed in this podcast argues cultures like the Aztecs and Maya wouldn't have thrived without nixtamalization.

Visualizing the chemistry of nuclear weapons

Nuclear weapons have devastating effects, but the science of how they work is atomically small. There are two main types of nuclear reaction: fission and fusion. The fission bomb produces immense energy by splitting an atom, the result of firing a...

How does cancer actually kill someone?

While the emotional and physical tolls of cancer are often clear, the innerworkings of how cancer kills can be confusing — and terrifying to discuss. Here, oncologists explain how cancer can progress.

Look through this WWI stretcher bearer's bag

While it was indeed the first industrialized war, medical science had yet to catch up on the battlefield. This nearly eight-minute video sorts through the contents of a World War I stretcher-bearer's satchel. A modern doctor and ex-officer assesses the bag's various medical tools for performing first aid on the battlefield.

The science (and scams) behind essential oils

Essential oils are a big business, with industry estimates pegging its market size at $10B last year—a number expected to double by 2030. These distilled plant compounds have a long history of both legitimate and exaggerated uses, and many marketed oils are, as the author of this long read claims, just selling wish fulfillment. Revisit some of the history and contemporary use of essential oils with this piece.

A step-by-step overview of the IVF process

In-vitro fertilization involves a sequence of complex steps to move from egg production to birth. This include stimulating egg production in the ovaries, egg harvesting and fertilization outside the body, embryo culturing and transfer, and methods to support in and increase the likelihood of full-term pregnancy.

Professional vocalists explain the mechanics of singing

Ever wonder how your favorite singer hits those high notes? Have you been amazed at someone bringing down the house at karaoke? The secret behind singing is that it's more technical than most realize. In this video, a handful of professional vocalists break down the basics to demonstrate how you can develop a more musical voice.

Cutting mold off your food does not make it safe to eat

Mold is a type of fungus, but not all fungi are molds. This video explains the value of mold, mold anatomy, health concerns around encountering and eating mold, and why mold is found all around us.

Visualize how CRISPR-Cas9—a type of immune system used by single-celled organisms to attack invasive viruses—targets and makes precise changes to a gene's DNA.

Read a deep dive on the 'all-purpose healing' peptide BPC-157.

Learn how your body is, scientifically, like a firework with its own slow, controlled burn.

Watch what the Ebola virus does inside our cells and organs in order to spread and survive.

Studies suggest when you sleep is as important as how much you get, and syncing with your circadian rhythms may lead to less fatigue and improved long-term health outcomes

To reduce wrinkles in clothing, research recommends gentle wash cycles with more water and tumble drying with smaller loads and longer times.

Tattoos remain visible on your skin thanks to immune cells called macrophages

Bone marrow (soft tissue found inside certain bones) generates roughly 500 billion new blood cells each day

Pure water does not conduct electricity because this flow of energy requires the movement of charged particles, and water is a neutral molecule.

Alzheimer's can lead to brain shrinkage, with an average of around 2% of volume reduction per year

After 25 people used virtual reality headsets to practice flying with virtual wings—flapping their arms—their visual cortex responded to the wings almost as if they were real arms, treating them as body parts.

Poison ivy is in the same family as mangoes, cashews, and pistachios—and they all produce oily urushiol in their raw, unprocessed state—but they are typically prepared in ways to avoid causing human discomfort.

The use of fungi to detoxify land and water—a process known as mycoremediation—has been used to clean up natural resources affected by the 2025 California wildfires.

While atoms are normally made of protons, neutrons, and electrons, exotic ones have been built with antimatter—alternate versions of normal matter that live for fractions of a second and are about a billion times as rare.

Volcanoes 'die' when their supply of magma runs out, if they are shifted away from their underlying magma reservoir, or if they get clogged by collapsing or their magma cooling back into rock.

Doctors differentiate between a phobia and fear by asking patients whether their fear interferes with their day-to-day activities.

The history of many kitchen appliances involves unexpected discoveries and applications, including wartime radar turned hamster defroster and replacing an 'ice king' with heat-stealing boxes.

Explore an interactive map built from more than 100,000 survey responses on where people find joy in their lives

The first steps to rebuilding your credit score include getting to know exactly what's on your credit report and figuring out how far you are from the '700 club,' or 'good score' range.

NBA superstar Victor Wembanyama spent the 2025 summer training with monks in central China to enhance his body and mind.

Power lines are dotted with large, brightly colored balls to improve the visibility of these thin wires to helicopters and small planes and help prevent potential crashes.

Corals are themselves not coral reefs—the term refers to the tiny marine invertebrates that build the rigid reef.

Track the location of the Voyager probes, currently between 13 and 15 billion miles away from Earth.

The Nasdaq's 'Magnificent 7' companies are responsible for roughly 40% of the Nasdaq 100 index's gains, while the remaining 93 companies account for the other 60%.

Meet the 56 signers of the Declaration of Independence—most of whom didn't put pen to paper until August 2, 1776—and see their original signatures.