How to increase vitamin D

Vitamin D is a fat-soluble vitamin your body needs to stay healthy. It helps maintain calcium balance in your blood and build and maintain bones. It is called the sunshine vitamin because we produce it through sun exposure. Low levels can affect bone health and have been linked to depression, fatigue, osteoporosis, osteomalacia, and rickets.

You can increase your vitamin D levels in three main ways: spending time in the sun, eating vitamin D–rich foods, and taking a supplement.

Increase your time in the sun

The major source of vitamin D comes from production in your skin when ultraviolet B (UVB) rays from sunlight convert precursors into vitamin D3. Factors affecting production include:

• Skin tone: darker skin has more melanin, which reduces vitamin D synthesis, requiring more sun exposure
• Age: older skin produces less vitamin D, and older adults often spend more time indoors
• Location: closer to the equator yields more UVB; northern or polluted areas yield less
• Clothing and sunscreen: protective clothing and sunscreen block UVB; just a few minutes of sun can start vitamin D production

Eat vitamin D–rich foods

Few foods naturally contain high vitamin D. Rich sources include:

• Fatty fish (mackerel: 3.5 oz ≈ 640 IU / 16 mcg), salmon, tuna, trout, shrimp, oysters, anchovies, sardines
• Mushrooms, egg yolks, beef liver
• Cod liver oil (1 Tbsp ≈ 1,360 IU)

Many foods are fortified (10–15% of the RDI per serving), such as milk, orange juice, yogurt, margarine, plant‑based milks, and breakfast cereals.

Take a vitamin D supplement

Supplements are the easiest and most effective way to raise levels. Forms include:

• Vitamin D2 (ergocalciferol) – prescription only
• Vitamin D3 (cholecalciferol) – over the counter

Research suggests D3 is more effective at raising and maintaining levels. Follow label directions and consult your provider before taking higher doses.

Vitamin D dosage

General recommendations:

• Birth to 12 months: 400 IU (10 mcg)
• 1 to 18 years: 600 IU (15 mcg)
• Adults 19 to 70 years: 600 IU (15 mcg)
• Adults over 70 years: 800 IU (20 mcg)
• Pregnant and breastfeeding: 600 IU (15 mcg)

Higher doses may be needed for deficiency or risk factors (malabsorption, liver/kidney disease, certain medications, gastric bypass, obesity). Only take the dosage recommended by your provider to avoid toxicity symptoms (nausea, vomiting, bone pain, kidney stones, arrhythmias).

Sources

• Vitamin D: Fact sheet for health professionals. Office of Dietary Supplements. Accessed May 27, 2025.
• Vitamin D content. USDA National Nutrient Database for Standard Reference. Accessed May 27, 2025.
• Chauhan K, Shahrokhi M, Huecker MR. Vitamin D. StatPearls. Updated Apr 9, 2023. Accessed May 27, 2025.