For most adults, commercially sold almond milk is safe to drink as a regular part of your diet. It’s low in calories, naturally free of lactose and dairy, and when fortified, provides reasonable amounts of calcium and vitamin D. That said, there are specific situations where almond milk poses real risks: for infants, for people with tree nut allergies, and for those prone to kidney stones. The safety picture also depends on what’s been added during processing.
Nutritional Gaps to Know About
Almond milk is mostly water. A typical cup contains only 1 to 2 grams of protein, compared to about 8 grams in cow’s milk. That protein gap matters if you’re relying on it as a primary milk replacement rather than just using it in coffee or cereal. The fat and calorie content is also significantly lower, which sounds like a benefit but means it delivers far less energy per serving.
Most commercial brands are fortified with calcium and vitamin D, but the numbers aren’t as strong as the label suggests. A cup of fortified almond milk typically provides 13 to 18 percent of the daily value for vitamin D. And the calcium added to plant-based milks, often in the form of tricalcium phosphate, has a bioaccessibility below 10 percent. That means your body absorbs far less of it than the calcium naturally present in dairy milk, which has a bioaccessibility around 30 percent. Research from a 2023 analysis found that you’d need roughly 1.5 to 3 servings of fortified almond milk to match the usable calcium from a single serving of skim milk. Shaking the carton helps, since fortified calcium tends to settle at the bottom.
Iodine Is the Overlooked Deficiency
Unless specifically fortified with iodine (and most brands aren’t), almond milk contains only about 2 percent of the iodine found in an equivalent serving of cow’s milk. Iodine is essential for your thyroid to produce the hormones that regulate metabolism, energy, and body temperature. People who switch entirely from dairy to unfortified plant milks without compensating through other iodine sources like seafood, eggs, or iodized salt risk gradually depleting their iodine levels. Over time, this can lead to an underactive thyroid or an enlarged thyroid gland.
Almond Milk Is Not Safe for Infants
This is the clearest safety risk. Almond milk should never replace breast milk or formula for babies under 12 months, and even after that age, it shouldn’t be a child’s primary milk source. It is too low in calories, protein, fat, and essential vitamins to support infant growth.
Clinical case reports published in ScienceDirect documented infants fed plant-based milks (including almond milk) who developed severe protein-calorie malnutrition with dangerous drops in blood protein levels, causing widespread swelling throughout the body. Other infants experienced seizures from critically low calcium, growth failure from insufficient caloric intake, severe iron deficiency anemia, and nutritional rickets from vitamin D deficiency. These weren’t edge cases of extreme neglect. They were families who believed plant milks were a healthy alternative. The earlier and more exclusively a baby is fed almond milk, the greater the danger.
UK government guidance reflects this clearly: only breast milk or infant formula should be used in the first 12 months. Fortified plant milks like almond or oat can be introduced as part of a balanced diet after age one, but not as a replacement for formula.
Tree Nut Allergies and Cross-Reactivity
Almond milk is an obvious concern if you have a confirmed almond allergy, but the risk extends further than that. Global estimates put tree nut allergy prevalence between 0.05 and 4.9 percent of the population, depending on the region and how the data is collected. What makes tree nut allergies tricky is the degree of cross-reactivity. The proteins in different tree nuts share enough structural similarity that sensitization to one nut often means reactivity to others. Among people with peanut allergy specifically, sensitization to tree nuts has been reported as high as 87 percent. If you have a known peanut or other tree nut allergy, almond milk warrants caution and allergy testing before you try it.
Kidney Stone Risk From Oxalates
If you’ve had calcium oxalate kidney stones, almond milk may not be a good choice. The National Kidney Foundation lists almond milk alongside soy and cashew milks as high in oxalates, compounds that bind with calcium in the kidneys and can form stones. This doesn’t mean almond milk causes kidney stones in everyone. For people with no history of stones, the oxalate content is unlikely to be a problem. But if you’re prone to them, switching to a lower-oxalate option like oat milk or fortified rice milk is a practical move.
Additives: Carrageenan and Emulsifiers
Many almond milk brands contain carrageenan, a seaweed-derived thickener used to improve texture. The safety debate around carrageenan has been ongoing for years, and the evidence is more nuanced than either side suggests.
Animal studies have shown that degraded carrageenan can trigger intestinal inflammation, reduce the diversity of gut bacteria, and increase intestinal permeability, sometimes called “leaky gut.” In mice, carrageenan worsened colitis when combined with a high-fat diet, partly by reducing beneficial bacteria like Akkermansia muciniphila while increasing harmful species. It also activated inflammatory signaling pathways in intestinal cells. Separately, studies on other common emulsifiers found in plant milks, including polysorbate 80 and carboxymethylcellulose, showed similar effects on gut bacteria and inflammation markers. A randomized controlled study in humans found that 15 grams per day of carboxymethylcellulose reduced bacterial diversity and short-chain fatty acid production in the gut.
The concentrations used in these studies are often higher than what you’d get from a daily glass of almond milk, so the real-world relevance for healthy people is unclear. Still, if you have inflammatory bowel disease or chronic digestive issues, choosing brands without carrageenan is a reasonable precaution. Many brands have already reformulated to use gellan gum or locust bean gum instead, and “carrageenan-free” is now a common label claim.
Aflatoxin and Cyanide Concerns
Almonds can carry aflatoxins, a group of naturally occurring mold-produced toxins that are carcinogenic at sustained exposure levels. A UK government risk assessment found that the margin of safety for aflatoxin exposure from almond drinks was well below the threshold considered low-concern, particularly for young children who consume it regularly. For adults drinking moderate amounts, the risk is lower, but it’s a reason almond milk shouldn’t be consumed in very large quantities daily, especially by small children.
Almonds also naturally contain amygdalin, a compound that releases small amounts of hydrogen cyanide when metabolized. Sweet almonds, which are used in commercial almond milk, contain very low levels. Bitter almonds contain much more. The same UK assessment found that if bitter almonds were hypothetically used to make almond drinks, the cyanide exposure could exceed safe limits for young children, potentially reaching toxic levels. Commercial almond milk is made from sweet almonds, so this scenario is unlikely in practice, but it underscores why buying from regulated, established brands matters.
Who Can Drink It Safely
Healthy adults without tree nut allergies or a history of kidney stones can drink almond milk safely as part of a varied diet. The key is not treating it as a nutritional equivalent to cow’s milk. It’s lower in protein, its fortified calcium is poorly absorbed, and unless the brand specifically adds iodine, it won’t support your thyroid the way dairy does. If almond milk is your primary milk, you’ll want to make up the difference through other protein sources, iodine-rich foods, and possibly a vitamin D supplement, since even fortified versions provide only 13 to 18 percent of the daily value per cup.
For children over one year old, fortified almond milk can be part of a balanced diet but shouldn’t be the sole milk source. For infants under 12 months, it is categorically unsafe as a breast milk or formula replacement.