Soy milk, almond milk and rice milk are the three top alternatives to dairy milk. They are regularly being compared against each other for nutritional value especially with regards to calcium. You need to consume at least 1,000 milligrams of calcium through diet every day to supply your body's demands. Dairy milk has long established itself as a rich source of calcium, containing about 300 milligrams of calcium per 8-ounce serving. However, if you are lactose intolerant or have casein allergies, getting calcium from regular milk is not an option. Therefore, choosing a calcium-rich nondairy alternative becomes important. By nature, dairy, soy, almond and rice have significantly different calcium contents, but the process of food fortification can generally level the calcium concentration among these products.

Calcium in Milk vs. Homemade Soy, Almond and Rice Milk

Dairy milk holds the highest amount of calcium compared to other milk alternatives. Drinking three cups of milk per day can effectively keep you safe from calcium deficiency. The naturally occurring calcium in soy is only about 1/6 of the amount found in dairy. Therefore, homemade soy milk contains only about 50 milligrams of calcium in each 8-ounce serving. Almonds and rice have even less calcium by nature. Each 8-ounce cup of plain almond milk contains a meager 2 milligrams of calcium, and less than 1 milligram is found in rice milk. Therefore, homemade or unfortified soy, almond and rice milk should not be used to replace cow's milk as a source of calcium.

Fortification: Calcium and Vitamin D

Brand name manufacturers like Silk, Blue Diamond and Rice Dreams make up for the insufficient levels of natural nutrition in their product. Because your body requires vitamin D to absorb calcium, these companies usually partner calcium fortification with an extra dose of vitamin D. Since cow's milk is already calcium rich, only extra vitamin D is added during food processing. After fortification, cow, soy, almond and rice milk are approximately equivalent in calcium and vitamin D concentrations, delivering about 30% of your daily need for calcium and 25% to 45% of vitamin D in each serving.

Calcium Absorption: Dairy vs. Fortified Alternatives

There are people who argue that natural calcium is easier to absorb than fortified calcium. The truth of this statement depends on several factors.

• Stomach Acidity: dairy is the only milk product that contains lactose which makes it more acidic. Higher acidity is more conducive to calcium absorption.
• Presence of phosphate: calcium absorption is limited by the presence of phosphate. Some brands of milk alternatives add calcium into their product as calcium triphosphate. These products show 25% reduced calcium absorption compared with cow's milk. Other products use calcium tricarbonate in fortification so that calcium absorption is equally as efficient as regular dairy.
• Precipitation of fortified calcium: one problem with fortified nutrients is that they can deposit at the bottom of the container over time. Therefore, the actual nutrient in the drink is much less than the total content. Shake your cartons well before consumption to avoid calcium precipitation.
• Estrogen: Soy milk contains plant estrogen that increases your body's ability to absorb calcium.