Vitamin D is a fat-soluble vitamin crucial for maintaining several aspects of health, including bone and teeth health, immune system function, and regulation of inflammation¹. It helps the body absorb and retain calcium and phosphorus, which are vital for building and maintaining bone tissue².

Sources of Vitamin D

1. Sunlight: The primary way our bodies produce vitamin D is through exposure to sunlight, particularly UVB rays³.
2. Food Sources: While few foods naturally contain vitamin D, some are fortified with it. Natural sources include fatty fish (such as salmon and mackerel), fish liver oils, egg yolks, and beef liver. Fortified foods may include dairy and plant milk, orange juice, and cereals⁴.
3. Supplements: For many, taking a vitamin D supplement may be necessary, especially during the months when sunlight exposure is limited⁵.

Health Benefits and Risks

• Bone Health: Vitamin D promotes calcium absorption, aiding in healthy bone and muscle function⁶. Deficiency can lead to conditions like rickets in children and osteomalacia in adults, characterized by bone pain and muscle weakness⁷.
• Potential Benefits: Some studies suggest vitamin D may have a role in reducing cancer cell growth, controlling infections, and reducing inflammation⁶. Research is ongoing to understand its full scope of benefits.

Recommended Intake

The Recommended Dietary Allowance (RDA) for adults is typically 600 IU (International Units) daily, increasing to 800 IU for those over 70 years old⁶. However, many health organizations suggest higher intakes might be beneficial, especially during times or in regions with limited sun exposure.

Safety and Toxicity

Overconsumption of vitamin D can lead to toxicity, resulting in harmful levels of calcium in your blood, leading to nausea, vomiting, weakness, and kidney problems⁶. The Tolerable Upper Intake Level (UL) for adults is set at 4,000 IU per day⁶.

For those unable to get sufficient vitamin D from sunlight or diet alone, considering supplements with the guidance of a healthcare provider is advisable⁵.

Footnotes

1. Benefits of Vitamin D in Health and Diseases ↩

2. Vitamin D: Benefits, deficiency, sources, and dosage ↩

3. Office of Dietary Supplements - Vitamin D ↩

4. Which foods are high in vitamin D? ↩

5. Vitamin D ↩ ↩²

6. Vitamin D ↩ ↩² ↩³ ↩⁴ ↩⁵

7. Vitamin D Deficiency - StatPearls - NCBI Bookshelf ↩