When people hear that you can’t eat dairy on the Paleo Diet, one of the main questions that arises is “Where do you get calcium?”
The short answer: Dairy is NOT the only way to get calcium. Providing your body with the optimal tools to process the calcium efficiently and properly is more important.
The amount of calcium required per day is mostly dependent on age and sex. Children aged 4 to 8 require 800mg per day while adolescents aged 9 to 18 require 1,300mg and adults require 1,000mg. Adults aged 51 or older, pregnant or nursing women and postmenopausal women require 1,200mg per day, notes the University of Michigan Health System.
It is widely known that dairy products are very high in calcium – they are almost the richest sources of calcium that humans ingest. However, what must be considered is how much calcium is excreted, aka. the “calcium balance”. The calcium balance is heavily influenced by the “acid-base” balance. When we eat foods like cereal, dairy products and legumes (non-Paleo) and even meats and fish (Paleo) our acid levels rise. Higher acid levels cause calcium to be excreted from our bodies. To manage an acid imbalance we need to eat alkaline foods, which are primarily fruits and vegetables, thereby preventing our acid levels from spiking and our bodies from dumping calcium.
The primary sources of Calcium in a Paleo Diet (PD) are dark leafy greens and other vegetables, as well as to a lesser extent eggs, fruits and seafood (such as sardines). Leafy greens, like kale and broccoli, not only contain adequate amounts of calcium, but they supply it in a form that is easier for the body to absorb and use. For example, spinach has 245 mg per cup when cooked and almonds have 231 mgs per 3 ounces (see more on the USDA Calcium Database).
One might compare this to a USDA recommended diet where the primary source of Calcium is typically dairy and grains. Under PD, while calcium levels may be slightly less than under traditional USDA diets, we are excreted much less as well. The amount of calcium that’ll be absorbed by the body on PD is likely going to be much higher than USDA since the cofactors for calcium absorption are higher across the board in the PD. Vitamin and mineral cofactors required for calcium absorption include Vitamin D (typically 4X greater in PD vs USDA) and Magnesium (1.25X in PD vs USDA).
Also, the high amounts of protein consumed under PD (often 20 to 30% of total calories) increases intestinal calcium absorption. Further, maintaining blood-sugar levels by preventing hyperinsulinemia that is commonly seen on a high-grain diet can decrease urinary calcium loss. Similarly, maintaining an acid/base balance as promoted under PD can decrease calcium leaching from bones (leading to osteoporosis), in contrast to the USDA diet rich primarily in acidic foods such as hard cheeses, cereal grains, salted foods, meats, and legumes.
So, by eating a diet that is not only fairly high in calcium from non-dairy sources but also providing balanced nutrition to allow for the absorption of calcium, it’s clear that the need for dairy in the diet as a calcium source is overstated and inaccurate. Furthermore, studies show that the phytic acid in grains (specifically whole wheat products in one study) reduces the absorption of dietary calcium from milk products, which would likely then leave the USDA diet at a much lower level of bio-available calcium than the PD. (source, and more information available HERE and HERE.)