Can You Get Enough Vitamin D From Milk?

December 24, 2025 •

4 min read

While most milk sold in the United States is fortified with vitamin D, providing around 100 IU per serving, it is a common misconception that you can get enough vitamin D from milk alone. Meeting your daily requirements typically requires a combination of fortified foods, sunlight, and sometimes supplements.

Quick Summary

Milk contains vitamin D primarily through fortification, not naturally occurring high levels. The amount is insufficient to meet daily needs from milk consumption alone, requiring a combination of sunlight exposure, other dietary sources, and supplements for adequate intake.

Key Points

Limited Natural Content: Raw and unfortified milk contains very small amounts of vitamin D naturally.
Fortification is Key: The vitamin D in most commercial milk is added during processing as a public health measure to prevent bone diseases like rickets.
Not a Complete Source: An 8-ounce cup of fortified milk (approx. 100 IU) provides only a fraction of the daily recommended vitamin D, which is typically 600-800 IU for adults.
Consider Other Sources: Relying solely on milk is insufficient; a combination of sunlight, fatty fish, fortified cereals, and supplements is often needed.
Risk Factors Exist: Factors like dark skin, age, limited sun exposure, and certain medical conditions increase the risk of deficiency regardless of milk consumption.
Milk Type Doesn't Matter: The amount of added vitamin D is generally consistent across whole, reduced-fat, and skim milk.
Supplements May Be Necessary: Many people, particularly those with risk factors, require supplements to maintain optimal vitamin D levels.

Milk's Natural vs. Fortified Vitamin D Content

Milk, in its raw and unfortified form, contains very little natural vitamin D. The significant vitamin D content found in most store-bought milk is a result of a fortification process that began in the 1930s to help combat rickets, a bone-weakening disease. Today, this practice continues as an important public health measure.

For example, an 8-ounce serving of fortified milk generally contains about 100 IU (International Units) of vitamin D, which is a small portion of the 600–800 IU recommended daily for most adults. The level of fortification is consistent across different types of milk—whole, 2%, 1%, and skim—and many plant-based milk alternatives are also fortified. However, the nutrient profile of unfortified raw milk is not standardized, and the vitamin D content is generally negligible.

Why Relying on Milk Alone Is Insufficient

While fortified milk is a "good" source, providing 10-19% of the recommended daily intake in the US, it is not a complete solution for vitamin D needs. The Institute of Medicine considers adequate intake for most adults to be 600 IU per day, and 800 IU for those over 70. Some research suggests even higher intakes may be needed to maintain optimal blood levels. Relying solely on milk would require an unrealistic daily intake, with some estimates suggesting a person would need to consume 40 or more glasses to achieve sufficient levels through this source alone.

Other Factors Impacting Vitamin D Status

Several factors influence your overall vitamin D status beyond diet:

Sunlight Exposure: The body produces vitamin D when skin is exposed to sunlight (UVB rays). However, factors like latitude, season, time of day, skin pigmentation, and sunscreen use can limit this production.
Skin Pigmentation: Individuals with darker skin produce less vitamin D from sun exposure and are at a higher risk of deficiency.
Age: The skin's ability to produce vitamin D from sunlight decreases with age, making older adults more vulnerable to deficiency.
Medical Conditions: Conditions that affect fat absorption, such as Crohn's disease, celiac disease, and ulcerative colitis, can hinder the absorption of dietary vitamin D.
Obesity: Higher body fat can sequester vitamin D, making it less bioavailable.

A Comparison of Vitamin D Sources


Source	Serving Size	Approximate Vitamin D (IU)	Notes
Fortified Milk	1 cup (8 oz)	~100	Offers a reliable, daily amount, but not a complete source.
Cod Liver Oil	1 tablespoon	1,360	Very high concentration, also contains Vitamin A.
Sockeye Salmon	3 ounces, cooked	570	A potent natural food source of Vitamin D3.
UV-Exposed Mushrooms	½ cup	366	Certain mushrooms treated with UV light are a plant-based source of Vitamin D2.
Sunlight	Dependent	Variable	The body's primary source, but efficiency varies by season, latitude, etc.
Supplementation	As directed	Variable	Reliable and consistent source, often necessary for those with limited sun exposure or dietary intake.

How to Ensure Adequate Vitamin D Intake

To achieve and maintain sufficient vitamin D levels, a multi-pronged approach is most effective. This typically includes a combination of dietary sources, limited safe sun exposure, and sometimes supplementation.

Here are some key strategies:

Incorporate a variety of food sources. Diversify your diet with other vitamin D-rich foods beyond fortified milk. Fatty fish like salmon, trout, and mackerel, as well as egg yolks and fortified cereals, can significantly boost your intake.
Consider sun exposure. For many, spending time outdoors in the sun during warmer months is a key source of vitamin D. Be mindful of sun safety, and remember that sun exposure is less effective in winter or for those with darker skin.
Read nutrition labels. The amount of vitamin D in fortified products can vary. Always check labels, especially for plant-based milks, to ensure they contain added vitamin D.
Explore supplementation. If your dietary intake and sun exposure are insufficient, a daily supplement is a safe and effective way to meet your needs. Many healthcare professionals recommend supplements for high-risk groups, such as breastfed infants, older adults, and those with limited sun exposure.

For more information on dietary needs and potential deficiencies, consult the Office of Dietary Supplements at the National Institutes of Health.

Conclusion

While vitamin D-fortified milk is a valuable dietary source that contributed significantly to public health by helping to eradicate rickets, it is not enough on its own to meet the daily vitamin D requirements for most people. An 8-ounce serving provides only a fraction of the recommended intake, and unfortified milk contains negligible amounts. Achieving adequate levels of this vital nutrient requires a holistic approach that includes a varied diet, safe sun exposure, and, for many, strategic supplementation. Milk plays a supportive role, but it is not a standalone solution for maintaining optimal vitamin D status.

Frequently Asked Questions

Most fortified milk, including cow's milk and many plant-based alternatives in the US, contains approximately 100 IU (International Units) of vitamin D per 8-ounce cup.

No, while fortified milk is a reliable source, it is not the most potent one. Sources like cod liver oil and fatty fish (salmon) contain significantly higher concentrations of vitamin D.

No, unfortified milk contains only trace amounts of naturally occurring vitamin D. Relying on it for adequate intake is not possible.

Fortification of milk with vitamin D began in the 1930s to help eradicate rickets and support bone health by enhancing the body's absorption of calcium.

It's likely. Given that milk provides only a fraction of the daily recommended vitamin D, many people—especially those with limited sun exposure or risk factors for deficiency—still need supplements to reach optimal levels.

No, the fortification process adds vitamin D to milk regardless of its fat content. Whole, 2%, 1%, and skim milk generally contain the same amount of added vitamin D.

Vitamin D from milk is readily absorbed, and some studies suggest that using milk as a delivery vehicle for supplements is effective. However, the total amount you absorb still depends on the concentration in the source.