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Building Your Bones
Calcium, Vitamin D and exercise are key
At every stage of life, nutrition plays a huge role in growing bones, preserving them, and preventing loss of bone density. Bone density refers to the strength of bones. The stronger they are the healthier they will be. Research tells a story about the relationship between calcium, vitamin D, and bone health. In November 2010, new recommendations based on scientific evidence were made. The goal is to ensure that all Canadians get enough calcium and vitamin D.
Calcium – the backbone of bone health
Most of the calcium in your body is found in the bones – about 99 per cent to be precise! The other one per cent fills crucial roles, including hormone balance, muscle function, and nerve transmission. The body requires this small amount of calcium to remain at a normal level in the blood at all times. Most of the calcium is stored in bone, but the body will take it out of storage when needed. When calcium becomes available again, it is replaced in the bones.
Your body functions quite well at maintaining all of these processes. However, you play a vital role with the food choices you make. Foods like milk, yogurt and cheese are rich sources of calcium. Vegans and vegetarians must make an effort to ensure they get enough calcium each day. Many fortified milk alternatives, fruit juice, tofu and some cereals provide calcium. Spinach, kale and broccoli have calcium, but it is in a form that is not absorbed easily. Choosing a variety of foods rich in calcium gives the body a helping hand, ensuring a healthy amount in the blood and bones.
| Age group | Recommended Dietary Allowance (RDA) per day | Tolerable Upper Intake Level (UL) per day |
| Infants 0 to 6 months | 200 mg* | 1000 mg |
| Infants 7 to 12 months | 260 mg* | 1500 mg |
| Children 1 to 3 years | 700 mg | 2500 mg |
| Children 4 to 8 years | 1000 mg | 2500 mg |
| Children 9 to18 years | 1300 mg | 3000 mg |
| Adults 19 to 50 years | 1000 mg | 2500 mg |
| Adults 51 to 70 years: | ||
| Men | 1000 mg | 2000 mg |
| Women | 1200 mg | 2000 mg |
| Adults 70+ years | 1200 mg | 2000 mg |
Pregnancy & Lactation |
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| 14 to 18 years | 1300 mg | 3000 mg |
| 19 to 50 years | 1000 mg | 2500 mg |
| * Adequate Intake rather than Recommended Dietary Allowance. | ||
Lack of calcium
If you do not get enough calcium, the body will take it out of your bones. Bones become soft and fragile. In children, bone softening is called rickets. In adults, it is called osteomalacia, and happens because bones absorb less calcium as we age. Women over age 50 and both men and women over age 70 need extra calcium. In spite of this, there is good news! By starting young, you can ensure that you have strong, healthy, and dense bones all the way through old age. Table 1 shows appropriate amounts of calcium for each age group.
Vitamin D is key
It is impossible to discuss bone health and calcium without talking about the key link, vitamin D. This nutrient plays a vital role in balancing the amount of calcium in the blood. It directly increases calcium absorption in the body. Without vitamin D, calcium cannot get into the bones or be maintained at normal levels in the blood. To have healthy bones, appropriate amounts of both calcium and vitamin D must be consumed.
Vitamin D occurs naturally in egg yolks and fish (such as salmon). Canadians also get vitamin D through fortified sources like milk and milk alternatives, fortified juices, and margarine. The skin produces vitamin D when exposed to sunlight of sufficient intensity. During the winter months in Canada, there are not enough UVB rays in the sunlight to help the body make vitamin D.
| Age group | Recommended Dietary Allowance (RDA) per day | Tolerable Upper Intake Level (UL) per day |
| Infants 0 to 6 months | 400 IU (10 mcg)* | 1000 IU (25 mcg) |
| Infants 7 to 12 months | 400 IU (10 mcg)* | 1500 IU (38 mcg) |
| Children 1 to 3 years | 600 IU (15 mcg) | 3000 IU (75 mcg) |
| Children 4 to 8 years | 600 IU (15 mcg) | 2500 mg |
| Children and adults 9 to 70 years | 600 IU (15 mcg) | 4000 IU (100 mcg) |
| Adults 70+ years | 800 IU (20 mcg) | 4000 IU (100 mcg) |
| Pregnancy & lactation | 600 IU (15 mcg) | 4000 IU (100 mcg) |
| * Adequate Intake rather than Recommended Dietary Allowance. | ||
Exercise – start young!
Think of calcium storage as a savings account. By banking calcium while young, children develop the foundation of their bone mass into adolescence for girls, and into young adulthood for boys. Along with calcium and vitamin D, exercise is an essential part of the equation. Exercise challenges and stresses bones, making them stronger. Sports and play help keep bones strong and growing.
While exercise is very important for children, it remains effective for teens, adults and the elderly too. Research shows that resistance training and balancing exercises continue to challenge bones at every stage of life, making them stronger and less fragile.
What if a person cannot have milk and milk alternatives?
Although milk and milk alternatives are the best sources of calcium and vitamin D, they are not the only choices. For some people, consuming milk products is not an option. This can occur if someone has lactose intolerance, a milk allergy, or does not eat or drink milk and milk alternatives.
Plant-based beverages offer an alternative to cow’s milk. They include soy, almond, rice, coconut and hemp milk. However, these are not all equal in nutrient value. Hemp, rice, coconut and almond milk all lack protein compared to cow’s milk. They may not be fortified with the same amount of calcium and vitamin D. Soy milk can provide the same amount of protein as cow’s milk. When fortified with calcium and vitamin D, it proves to be a great milk alternative. Unlike the others mentioned, this beverage is on the list of milk and milk alternatives in Eating Well with Canada’s Food Guide.
To supplement or not to supplement
Calcium – In a 2010 scientific review on calcium, researchers found most people are getting enough calcium from food and beverages. If a calcium supplement is required for any reason, there are two types to choose from: calcium carbonate and calcium citrate. Calcium carbonate is the most common form, and is best taken with food. Calcium citrate is more expensive, and absorbs equally well with or without food.
Calcium supplements contain varying amounts of elemental (absorbable) calcium. The amount is listed on the product label.
Vitamin D – Breastfed infants and adults over age 50 both need vitamin D supplements. Breast milk does not contain vitamin D, which is needed for adequate bone growth in infancy. A daily supplement of 400 IU of vitamin D is required. In Canada, infant formulas must be fortified with vitamin D.
Canadians over age 50 lose the ability to absorb vitamin D efficiently. They are at risk of osteoporosis. Health Canada advises adults over 50 to take a daily vitamin D supplement of 400 IU. Vitamin D supplementation is considered safe. The most effective form is Vitamin D3. However, if you wonder whether you need it, ask your doctor for a routine serum vitamin D test.
At every age, calcium and vitamin D, combined with regular exercise, will build and preserve bones. Research shows that it is never too late to start thinking about bone strength.
FAMILY HEALTH is written with the assistance of |
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FAMILY HEALTH is written with the assistance of |
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