Calcium and Vitamin D

Nutrition, December 10, 2016

Getting the right daily amount of calcium is far more than just having a glass of milk. I'll try and outline whats required for you to get your optimal daily dose of this very important mineral.

True calcium deficiencies are uncommon with a balanced diet. A bigger concern for endurance athletes is that they are not able to utilise the calcium that they take in. Poor calcium metabolism rather than a deficiency is more of an issue. This results in not enough of this vital nutrient getting into bone, muscle, and other tissue. Excessive calcium is then potentially deposited in joints, tendons, ligaments, or even kidneys.

In order for our bodies to metabolise calcium and absorb it well from food you must have sufficient Vitamin D. The ancient Greeks believed that athletes should be well bathed in sun (their elite athletes trained naked on the beach). Research has shown that good Vit D levels are associated with peak athletic performance. Of course with NZ's harsh sun it is important to balance sun exposure so you don't risk getting burnt. Normal Vit D improves muscle function, prevent bone issues, aid recovery, and reduces aches/pains and many other health problems. Vit D isn't really a vitamin - it's really a unique steroid hormone that helps control inflammation and immunity. One of it's many roles (among promoting the work of several thousand genes) is regulating calcium (and phosphate) absorption and utilisation. Proper fat metabolism is needed for vit D production,  those with too high or low body fat %'s may be unable to release stored Vit D. 

Measuring Vitamin D.

This can be done with a simple blood test. "Normal" Blood levels should be between 50-80ng/mL. The daily needs are usually higher than what recommendations state. The average need for some may be as high as 4000 IU a day. Some of the recommendations I have found are around 600-1000 IU/daily.

Sources of Vitamin D

Our primary source comes from the sun with foods providing very small amounts. Exposing your arms and legs to sunlight for 20-30min a day between the hours of 10am and 3pm without sunscreen (SPF 30 can reduce Vit D production by 95%) may be adequate for building healthy Vit D levels (Some studies I have read state that you should aim for 1500 hrs of sun exposure during the year) This could produce up to 5000 IU. Interestingly we can't overdose on Vit D from the sun like we can from food sources. The best food sources are wild salmon, sardines, and some mushrooms. Foods fortified with Vit D are not a good source. One supplement is cod liver oil (contains Vit D3 which is better utilised than Vit D2). Our family use a spray (Garden of Life - Vegan D3 organic spray) which provides 1000 IU per spray in a vanilla flavour. This is sourced from Lichen. 

Magnesium is important to help regulate Vit D. This mineral is often low in athletes. The best sources are vegetables, seeds and nuts.

Calcium Rich Foods

Consuming calcium rich foods doesn't mean dairy (dairy fats are high in B fat and contribute to inflammation). Here are some foods that contain calcium (single serve) Salmon 225mg, Almonds 100mg, Spinach (100g = 3.3 cups raw, 1/2 cup cooked) 135mg, Green Beans (1 cup = 20 beans) 100mg. In general smaller amounts of calcium are better absorbed than larger amounts wheather from food or supplements. So if you are taking a supplement it may be best to take a lower dose more often throughout the day. Even though vegetables contain smaller amounts of calcium larger %'s are absorbed compared to milk. In some situations a serving of broccoli may result in more calcium getting into the body than a serving of milk.

ELIMINATE soft drinks

Excess phosphorus intake can be detrimental for calcium use - pulling it out of muscles and bones. Many soft drinks contain large amounts of phosphorus. People who dink these excessively risk significant calcium loss form bones, and muscles.  In my university days I bought 2L of coke a week, now I only have 4-6 servings a year as a treat during a movie. 

I hope this helps unpack the symphony required by different vitamins and hormones to create optimised bone health. Don't be caught up with reductionist advice and ensure you are have enhancing daily bone health habits in place.