There are several pros and cons to going Vegan. If you are Vegan, more power to you, but an article from Food Business News on Nutrition and Bone Health is why I’m glad I drink milk.
Two-and-a-half to three servings of dairy products such as low-fat milk and yogurt were associated with higher bone density, according to a study by the Institute for Aging Research (IFAR) involving over 3200 participants.
What about calcium supplements?
Well, that study doesn’t specify, but this one does:
A high intake of supplemental calcium (but NOT dietarycalcium) was associated with higher risk of death by cardiovascular disease or heart disease in men. This association was determined by scientists at the National Cancer Institute, who reviewed data on 388,000 participants in the National Institues of Health-AARP Diet and Health Study. Supplemental calcium was not associated with cardiovascular death (CVD) or heart disease death in women, but dietary calcium was not associated to CVD death in men or women.
If I am now weary about calcium supplements and I still don’t want to drink milk, what can I do?
The alternative to calcium supplementation is, of course, low-fat dairy, and also beans and green leafy vegetables.  In fact, vegan or non-vegan, EVERYONE should try to consume as many dark green leafy vegetables as possible.
OK, why?
Vitamin K! Okay? Okay.  Oh, K…

Dark green leafy vegetables are the best source of Vitamin K, and vitamin K helps a protein called osteocalcin get in the proper form (its ‘carboxylated form’) for bone building. Osteocalcin plays a significant role in maintaining bone strength, but it has to be carboxylated to get absorbed into the bone. (Unless you’re a chemist, don’t worry about carboxylation – the point is this protein has to be a certain way to work, just like your umbrella when it’s raining). Getting sufficient Vitamin K from the diet is the best way to make sure this bone-building protein can do its thing.

So I still don’t need to drink milk, do I?

Well…
Osteocalcin is a protein, and amino acids (the building blocks of protein) are needed for protein synthesis in bone. Getting enough protein is therefore just as important as getting enough Vitamin K and calcium. Dark leafy greens help you get calcium and Vitamin K, but not so much with the protein. Furthermore, it’s not just the amount of protein, but the type. You need enough of all the right amino acids for your body to work properly, hence the term “complete protein”. Milk is a complete protein but plant foods have to be combined to provide all the right amino acids (for example, beans and rice provide all the right amino acids, so they’re called ‘complimentary proteins’).
So I STILL don’t need to drink milk, I just have to plan my proteins so I make sure they’re complimentary.
Correct! That works, as long as you’re good at planning. Personally, I’d rather just do one-stop-shopping with a glass of milk and then add green leafy veggies to lunch and dinner. Vitamin K, check. Calcium, check. Protein, check.
The caveat here is that bone health depends on getting enough of all three: calcium, vitamin K and protein.  

Consuming three servings of milk or yogurt (ice cream doesn’t count) is great for providing the protein and calcium, but you really can’t afford to skimp on the green leafy vegetables. Not only do the leafy greens provide calcium and vitamin K, but they also help your body stay neutral. When you get too much protein and not enough veggies, your body gets a little acidic (think lemon juice). Oxidizing/metabolizing certain proteins results in excess acids that have to be excreted. Your body can only lower the acidity level in your urine so much (or it’ll REALLY damage your insides!). Using a buffer, something slightly basic (think baking soda or toothpaste) will make the urine as neutral (think water) as possible. Vegetables provide buffers, but without enough veggies your body will borrow the buffers from the bone.

Science hasn’t caught up to the boom in alternative milks (almond milk, rice milk etc) so no one can say for sure whether drinking these products will give your body the same benefits as low-fat milk. Since women reach peak bone mass before their thirties, I’m going to continue drinking plenty of milk and double-up on the leafy greens.
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