Vitamin D in Winter: How Much You Need and Why

Last updated November 6, 2026

Many people get less vitamin D in winter because shorter days mean less sunlight. Your body makes vitamin D when sunlight hits your skin. In winter, you can get more from fatty fish, eggs and fortified milk. Some people may also need a supplement.

Most adults aged 19 to 70 need 600 international units (IU) a day. Adults over 70 need 800 international units (IU). Talk to your doctor before starting any supplement.

This article is for general information only. Too much vitamin D can be harmful, so do not take high doses without medical advice.

Key Takeaways

• Sunlight helps your body make vitamin D, but winter sun is weaker.
• Most adults need 600 international units (IU) a day, and those over 70 need 800 international units (IU).
• Fatty fish, eggs and fortified foods are good sources.
• A simple blood test can check your vitamin D level.
• Too much vitamin D from supplements can cause harm.

On This Page

• Why Vitamin D Matters
• Why Winter Lowers Vitamin D
• How Much You Need
• Best Food Sources
• Should You Take a Supplement?
• When to Get Help
• How Your Body Makes Vitamin D
• Factors That Affect Vitamin D Levels
• Balance Sun and Skin Safety
• Easy Ways to Add Vitamin D Foods
• Vitamin D and Calcium Work Together
• Vitamin D for Babies and Children
• Talk to Your Doctor About Testing
• Store Supplements Safely
• Plan Vitamin D-Friendly Winter Meals

Why Vitamin D Matters

Vitamin D helps your body absorb calcium. That keeps your bones strong.

It also plays a role in muscle function and your immune system.

Why Winter Lowers Vitamin D

In winter, the sun sits lower in the sky, and days are shorter. Many people also spend more time indoors and cover up with warm clothes.

People with darker skin and older adults may make less vitamin D from sunlight, too.

How Much You Need

The National Institutes of Health (NIH) Office of Dietary Supplements lists daily amounts by age.

Best Food Sources

Few foods naturally contain much vitamin D. These are some of the best.

MedlinePlus lists foods that contain vitamin D.

• Salmon, trout and sardines
• Egg yolks
• Fortified milk and plant milks
• Fortified orange juice and cereals
• Mushrooms exposed to ultraviolet (UV) light

Use this calculator to estimate your vitamin D from food.

Should You Take a Supplement?

Some people may benefit from a supplement in winter. Your doctor can check your level with a simple blood test.

The Food and Drug Administration (FDA) explains what to know about dietary supplements.

Do not take more than recommended unless your doctor tells you to. Very high doses can raise calcium levels and cause nausea, weakness or kidney problems.

• Eat fatty fish twice a week
• Choose fortified milk or cereal
• Add eggs to meals
• Get midday daylight
• Ask about a blood test
• Avoid high doses without advice

When to Get Help

Talk to a doctor before taking high doses, and get help if you notice these signs.

• Ongoing bone pain or muscle weakness
• Nausea, vomiting or confusion while taking supplements
• Very frequent thirst or urination while taking supplements

The National Institutes of Health Office of Dietary Supplements explains vitamin D needs and risks.

How Your Body Makes Vitamin D

Your skin makes vitamin D when sunlight hits it. Ultraviolet (UV) rays from the sun start the process.

Your body then changes vitamin D into an active form it can use. Your liver and kidneys both play a part.

Food and supplements give you vitamin D too. Your body processes it the same way.

Factors That Affect Vitamin D Levels

Many things affect how much vitamin D your body makes or absorbs. Some you can change, and some you cannot.

If several of these apply to you, talk with your doctor. They can help you decide whether a test makes sense.

Balance Sun and Skin Safety

Sunlight helps your body make vitamin D. Too much sun can also damage your skin.

Short periods outdoors can help, but sunburn raises skin cancer risk. Protect your skin with sunscreen, hats and shade when the sun is strong.

Many health experts suggest getting vitamin D from food and supplements rather than extra sun exposure. Ask your doctor what is right for you.

The American Academy of Dermatology (AAD) explains how to protect your skin from the sun.

Easy Ways to Add Vitamin D Foods

A few simple swaps can add vitamin D to your meals.

• Choose fortified milk or plant milk for cereal and coffee.
• Add canned salmon or sardines to salads and sandwiches.
• Cook eggs for breakfast a few times a week.
• Look for mushrooms grown under ultraviolet (UV) light.
• Check labels on yogurt and orange juice for added vitamin D.

Read nutrition labels to compare products. The amount of vitamin D can vary a lot between brands and product types.

The Centers for Disease Control and Prevention (CDC) explains how to read the nutrition facts label.

Vitamin D and Calcium Work Together

Vitamin D helps your body absorb calcium from food. Calcium builds and maintains strong bones.

Good calcium sources include dairy, fortified plant milks, leafy greens and canned fish with bones.

Eating both nutrients together supports bone health. A balanced diet with a variety of foods makes this easy.

Vitamin D for Babies and Children

Babies and children need vitamin D for growing bones. Their needs differ from adults.

Breast milk usually contains only small amounts of vitamin D. Many doctors recommend a vitamin D supplement for breastfed babies.

Ask your child’s doctor about vitamin D needs at checkups. Follow their advice on supplements and dosing.

Talk to Your Doctor About Testing

A simple blood test can check your vitamin D level. Not everyone needs one.

Your doctor may suggest a test if you have risk factors or certain symptoms. They will explain what your results mean.

Never start high-dose supplements without medical advice. Too much vitamin D can cause harm.

Store Supplements Safely

Vitamin D supplements can look like candy, especially gummies. Keep them away from children.

Store supplements in their original containers, high up and out of reach. Close the lid tightly after each use.

If a child swallows supplements, call Poison Control at 1-800-222-1222 right away.

Plan Vitamin D-Friendly Winter Meals

Building a few meals around vitamin D foods makes winter eating easier. Here are some simple ideas.

• Breakfast. Scrambled eggs with fortified milk and whole grain toast.
• Lunch. A salmon salad sandwich with leafy greens.
• Snack. Fortified yogurt with berries.
• Dinner. Baked trout with roasted vegetables and rice.

Rotate these meals through the week. Pair them with plenty of fruits and vegetables for balanced nutrition and steady energy.

Vitamin D Mistakes to Avoid

Some habits can lead to too little or too much vitamin D. Watch out for these common mistakes.

• Taking high doses without talking to a doctor
• Assuming a sunny winter day gives enough vitamin D
• Forgetting vitamin D in children’s diets
• Skipping foods that naturally contain it

Talk to your doctor before starting any supplement. They can suggest the right amount for you.

Build Healthy Winter Habits

Small habits help you feel your best during the darker months. They also support your overall health.

Spend time outside during daylight when you can. Eat a balanced diet with fish, eggs and fortified foods.

Information Only

This article is for information only and is not medical advice.

Talk to a doctor about any health concerns or questions about vitamin D.

Test Yourself

Frequently Asked Questions

Why do I get less vitamin D in winter?

Shorter days, weaker sun and more time indoors mean less sunlight on your skin.

How much vitamin D do adults need?

Most adults need 600 international units (IU) a day. Adults over 70 need 800 international units (IU).

What foods have vitamin D?

Fatty fish, egg yolks and fortified milk or cereal are good sources.

Can you take too much vitamin D?

Yes. Very high doses from supplements can be harmful.

Does darker skin make less vitamin D?

Yes. Darker skin makes less vitamin D from the same amount of sunlight.

Is it better to get vitamin D from the sun or from food?

Many experts suggest food and supplements, since too much sun can damage skin.

Do babies need vitamin D supplements?

Many doctors recommend them for breastfed babies. Ask your child’s doctor.

Should I get my vitamin D level tested?

Ask your doctor. They may suggest a test if you have risk factors or symptoms.

Wrapping Up

Add a few vitamin D foods to your meals this week. If your level worries you, ask your doctor about a blood test.

Feeling low in the dark months? Read about seasonal affective disorder. Keep moving with our tips to stay active in winter.

Editor’s Note

This guide is accurate as of November 6, 2026. It is for general information and does not replace advice from a doctor.

Spot an error in this article? Please contact us at support@digieh.com or read our Corrections Policy.

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