The nutrient is also needed to maintain bone and muscle health since it aids the absorption of calcium, magnesium and phosphate. Its deficiency manifests itself in several symptoms, such as muscle and bone pain, especially fatigue. 

What is the minimum requirement for adequate vitamin D levels age-wise on a daily basis?

• Children below one year old - 400 IU
• Children up to 13 years old - 600 IU
• Adults and pregnant women - 600 to 800 IU

Plant sources are few and far between, while vitamin D is primarily present in animal sources of food. Here are some of the important sources of vitamin D to include in your diet, according to a recent article on Healthline.

Supplements

The supplements are available in large doses in either vitamin D3 or vitamin D2 forms. About 50,000 IU (1,250 mcg) raises vitamin D levels in the blood to a higher amount. However, D3 is more effective than D2 when consumed in smaller doses every day. 

Fortified Food

Countries have different rules on fortifying products, either for dairy products or cereals. Cow’s milk, non-dairy beverages (soy, oat, almond, hemp milk or orange juice), yogurt, tofu and cereals are examples of fortified products that have 100 to 300 IU per day. 

Sunshine

Direct sun exposure without sunscreen up to 30 mins twice a week is sufficient to reach optimal vitamin D levels, as per the National Institute of Mental Health. Skin color, pollution, smog, time and seasons are some of the factors that influence the absorption of vitamin D. 

Egg Yolks and Cheese

Egg yolks from well-bred chicken that were reared outdoors hold ample amounts of vitamin D. Cheese in small amounts also boasts of vitamin D. 

Mushrooms

Wild mushrooms with exposure to UV rays have enough vitamin D. Even mushrooms grown with artificial exposure to UV light may provide 3.8 and 28 mcg per 100 grams. They can be as effective as the supplements and do not deteriorate with decreasing shelf life, though most commercial varieties have little exposure to vitamin D.