What vitamins does milk lack?

October 25, 2025 •

4 min read

While milk is a powerhouse of calcium and protein, it does not provide a complete nutritional profile. Understanding what vitamins does milk lack is crucial for building a balanced diet that accounts for its natural deficiencies and for benefiting most from fortified versions.

Quick Summary

Milk is notably deficient in Vitamin C and other key nutrients, including Vitamin E and iron. Fortification and a diverse diet are essential for bridging these nutritional gaps to ensure overall wellness.

Key Points

Vitamin C: Milk contains only trace amounts of Vitamin C, with pasteurization and storage further reducing its levels.
Fat-Soluble Vitamins (E & K): Vitamins E and K are found in milk in minimal quantities, meaning it is not a reliable dietary source.
Vitamin D Fortification: The majority of milk sold commercially is fortified with Vitamin D to prevent rickets and promote calcium absorption.
Processing Effects: Pasteurization and light exposure can slightly decrease water-soluble vitamins like Vitamin C and riboflavin, but do not significantly affect major nutrients like calcium and Vitamin D.
Iron Absorption: Milk is a poor source of iron and can inhibit its absorption from other foods, which is a particular concern for toddlers.
Balanced Diet: To cover nutritional gaps, milk should be complemented with Vitamin C-rich foods and other sources of Vitamins E, K, and iron.

Milk's Nutritional Profile: The Missing Pieces

Milk is a staple in many diets, celebrated for its rich content of calcium, phosphorus, and high-quality protein. It is also naturally a good source of several B vitamins, including B12 and riboflavin. However, relying solely on milk as a primary source of all essential nutrients would be a mistake, as it is naturally lacking or has minimal amounts of several key vitamins and minerals.

The Most Significant Deficiency: Vitamin C

Perhaps the most notable vitamin that milk lacks is Vitamin C, or ascorbic acid. While raw, fresh milk may contain trace amounts, these levels are not nutritionally significant and are highly susceptible to being destroyed by heat and light during pasteurization and storage. Humans, unlike most mammals, cannot produce their own Vitamin C and must obtain it from their diet. This is why relying on milk for Vitamin C is not viable. Excellent sources of this crucial antioxidant include fruits like oranges and berries, and vegetables such as bell peppers and broccoli.

Other Low or Deficient Nutrients

In addition to Vitamin C, unfortified milk is also a poor source of other important vitamins and minerals:

Vitamin E: Found in very low quantities. This fat-soluble antioxidant is important for protecting the body from damage caused by free radicals.
Vitamin K: Also present in minimal amounts. This fat-soluble vitamin plays a vital role in blood clotting and bone health.
Folate (Vitamin B9): Unfortified milk contains only small amounts of this B vitamin, which is crucial for cell growth and metabolism.
Iron: While not a vitamin, iron is a critical mineral that milk contains in negligible amounts. Furthermore, milk proteins (casein and whey) and calcium can inhibit the body's ability to absorb iron from other foods. This is a significant concern for toddlers who drink excessive amounts of cow's milk, potentially leading to iron deficiency anemia.

The Role of Fortification: How Milk is Enhanced

Most commercially sold milk in many countries is fortified with vitamins to compensate for natural deficiencies and losses during processing. This is a public health strategy to prevent nutritional deficiencies like rickets, which is caused by a lack of Vitamin D. The most common fortification includes:

Vitamin D: Milk naturally contains very little vitamin D. Fortification dramatically boosts its content, which is crucial for calcium absorption and bone health.
Vitamin A: In reduced-fat milks, Vitamin A is removed along with the fat content during processing. It is then added back in through fortification to match the levels found in whole milk.

Processing and its Impact on Milk's Vitamin Content

Pasteurization, the process of heating milk to kill harmful bacteria, has a minimal impact on most nutrients. However, certain vitamins are more susceptible to degradation. Water-soluble vitamins like Vitamin C and some B vitamins can be slightly reduced, especially during ultra-high-temperature (UHT) processing. Moreover, exposure to light can degrade riboflavin and Vitamin A, which is why milk is typically sold in opaque cartons.

Comparison: Unfortified vs. Fortified Milk


Nutrient	Unfortified Cow's Milk	Fortified Cow's Milk (Typical US)
Vitamin C	Trace amounts	Trace amounts
Vitamin D	Trace amounts	Excellent source (added)
Vitamin A	Dependent on fat content	Consistent, high source (added)
Vitamin E	Minimal amounts	Minimal amounts
Vitamin B12	Good source (natural)	Good source (natural)
Iron	Negligible amounts	Negligible amounts
Calcium	Excellent source (natural)	Excellent source (natural)

How to Create a Balanced Diet with Milk

Since milk is not a complete source of vitamins, it is important to build a balanced diet that includes foods rich in the missing nutrients. A strategy would be to enjoy your glass of milk alongside a high-vitamin C food, like a bowl of strawberries, to aid iron absorption. To get sufficient Vitamin E, incorporate nuts, seeds, and leafy greens. For Vitamin K, add more dark, leafy greens to your meals. The key is to see milk as part of a larger nutritional puzzle, filling some gaps but not all of them.

Conclusion

While milk is an outstanding source of calcium, protein, and several B vitamins, it is not a perfect food and what vitamins does milk lack is a critical question for nutrition. Primarily, it lacks nutritionally significant amounts of Vitamin C, E, and K, and is not a good source of iron. Modern fortification has effectively addressed the Vitamin D and Vitamin A shortfalls, making commercially available milk a much more balanced product. However, consumers must still ensure a varied diet including fruits, vegetables, and other sources to get all the essential vitamins and minerals their body needs.

For further reading, consult authoritative sources on nutrition, such as this Health Professional Fact Sheet on Vitamin C from the National Institutes of Health.(https://ods.od.nih.gov/factsheets/VitaminC-HealthProfessional/)

Frequently Asked Questions

While pasteurization and light exposure can reduce the levels of water-soluble vitamins like Vitamin C and riboflavin, the loss is generally minor. Most major nutrients, including calcium and fortified Vitamin D, remain stable.

No, milk is not a good source of Vitamin C. Any trace amounts found in raw milk are often lost during processing and storage. To get sufficient Vitamin C, it's best to consume fruits and vegetables.

Milk is fortified with Vitamin D to make it a reliable source of this nutrient, which is essential for the body to absorb calcium. This practice helps prevent diseases like rickets, especially in regions with limited sunlight.

Yes, milk contains components like calcium and certain proteins that can slightly inhibit iron absorption from other foods. This is particularly relevant for infants and toddlers who rely heavily on milk.

Fortified milk has added nutrients, most commonly Vitamin D and Vitamin A. Unfortified milk contains only the nutrients that are naturally present. Fortified milk is the standard for most commercial milk products.

Yes. While whole, 2%, and skim milk can all be fortified, fat-soluble vitamins like A and D are added back to lower-fat versions during fortification to ensure consistency. Plant-based milks have different natural profiles and are often fortified to match cow's milk.

To supplement milk's natural deficiencies, include plenty of Vitamin C-rich fruits and vegetables (e.g., oranges, broccoli), Vitamin E sources (e.g., nuts, seeds), and Vitamin K sources (e.g., leafy greens) in your diet.