Vitamin D: What It Does, Where to Get It, and How Much You Need
Vitamin D helps your bones, muscles, and immune system. Your skin makes it when sunlight hits it. You can also get it from a few foods and from supplements. Low vitamin D is common if you avoid sun, live far north, have darker skin, or spend most time indoors. This page gives clear, useful steps to check your levels and improve them safely.
How to Get Enough Vitamin D
Sunlight: 10–30 minutes of midday sun on arms and legs two to three times a week often helps most people. Shorter times work for fair skin; darker skin needs longer. Wear sunscreen after the brief unprotected exposure. If you’re at high risk for skin cancer or live in winter with little sun, don’t rely on sunlight alone.
Food: Fatty fish (salmon, mackerel, sardines) are the best natural sources. Fortified milk, orange juice, and cereals help too. One large egg yolk has a small amount. If you follow a vegan diet, look for fortified plant milks or lichen-based D3 supplements.
Supplements: Vitamin D3 (cholecalciferol) is generally better at raising blood levels than D2. Take supplements with a meal that contains fat — vitamin D is fat-soluble and absorbs better that way. Pick a reputable brand and check the label for IU per dose.
Testing, Dosage, and Safety
Test: Ask your doctor for a 25-hydroxyvitamin D blood test if you feel fatigued, have bone pain, frequent infections, or risk factors like obesity or older age. Most labs report values in ng/mL. Many experts consider under 20 ng/mL deficient, 20–30 ng/mL insufficient, and 30–50 ng/mL adequate for most people.
Typical dosages: For most adults, 600–800 IU/day covers basic needs. People over 70 often aim for 800–1,000 IU/day. If tests show deficiency, doctors commonly recommend 1,000–4,000 IU/day or a short course of higher doses under supervision. Don’t self-prescribe very high doses long-term without medical follow-up.
Safety: Vitamin D toxicity is rare but real. Too much can cause nausea, weakness, high blood calcium, and kidney stones. Watch for interaction with medications like steroids, some weight-loss drugs, and certain anticonvulsants that can lower vitamin D levels. If you take calcium supplements, your doctor may monitor levels more closely.
Quick tips: Take D3 with a meal that has fat. If you’re vegan, choose D2 or lichen-derived D3. If you have chronic conditions, ask your doctor before starting supplements. Re-test after a few months if you start treatment to check progress.
Vitamin D is simple to manage when you know the basics: sensible sun, a few right foods, and the correct supplement dose checked by a test when needed. Small, consistent steps usually fix low levels and help you feel better.
