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Vitamin D RDA for women

Can I know what is the exact daily requirement of calcium and vitamin d for my body. I am 31, female.


For calcium, the recommended daily allowance for an adult woman is 1000mg per day. Regarding Vitamin D the RDA has been reviewed and is currently set at 600iu for women 19-50.

Vitamin A in pregnancy

I am 19 weeks pregnant and started tracking my nutrition. I do not eat meat, but I do consume dairy and eggs. My food consumption from dairy, eggs, fortified cereal, and fruits/vegetables is always around 780 mcg (sometimes a little more sometimes less). I take a prenatal vitamin with 4000 IU of Vitamin A as beta carotene (which I believe is around 2400 mcg). My question is whether the Vitamin A in my prenatal, since it is Vitamin A as beta carotene, could cause me to have Vitamin A toxicity (i.e., birth defects) combined with the food I eat, or whether my body will treat it like the beta carotene in vegetables and only use what it needs?


If your pre-natal formula only contains Beta Carotene, as oppose to Vitamin A in the form of Retinol then you should be fine. Beta Carotene has not been associated with toxicity in Humans or Animals. Only Vitamin A in the form of Retinol has been associated with birth defects. The USRDA (recommended daily allowance) established by the Food and Drug Administration is 8,000 IU/day for Vitamin A whereas the National Research Council’s recommended dietary allowance for vitamin A during pregnancy is equivalent to 3,300 IU as retinol, or 5,000 IU of vitamin A from the your diet as a combination of retinol and bet carotene. Dairy products are often fortified with Vitamin A, but as you are not consuming them, this is not a problem. Oily fish such as mackerel, trout, herring, cod and salmon are also rich in retinol. I would recommend switching to some natural unfortified cereals. As a rule fortified cereals, are fortified because of the heavily processed grains that have had all the beneficial nutrients striped from them. They could be considered nutritionally dead once they have been processed. I would suggest looking for an organic un-fortified cereal such as oatmeal as an alternative. To summarise, based on your current diet, your consumption of total Vitamin A from retinol and beta-carotene falls within the current guidelines.

Vitamin Packets

When taking vitamin packets, should you take all the vitamins at once or split and take in two doses.


Thanks for your question, it depends on the specific product you are taking. Normally there should be some instructions listed on the bottle or packaging. In general there are some vitamins and minerals that compete for absorption or inhibit the absorption of others. Vitamin C can inhibit copper absorption, and large amounts of copper can lead to vitamin C deficiency. Zinc inhibits copper and iron, magnesium and calcium also compete for absorption. Fat-soluble vitamins A, D, E and K require fats to be absorbed so should be taken with a fat containing meal. For this reason some multivitamin formula’s are sold in packs where they can be split up and taken at different times of the day to optimise absorption. On that basis, yes they should be split into multiple doses, but as I originally mentioned, I would suggest following the product specific instructions.

Iron-fortified cereal with milk

I am trying to make sure I get enough calcium and iron in my diet. Is it bad if I am eating iron fortified mini-wheats with milk–am I messing up my absorption of iron and calcium since they seem to cancel each other out? I got the cereal because it had lots of iron, but I wondering how much I absorb if I drink it with milk–so I didn’t know if it just better to get a non-fortified to better absorb the calcium.


Thanks for your question. First recommendation would be to suggest you do not skip breakfast. Skipping breakfast can slow your metabolism and lead to fat gain, not the kind of weight gain that I would recommend. If your goal is weight gain, then I would recommend trying to gain weight in the form of muscle. Muscle has numerous health benefits going beyond the cosmetic aspect. Research indicates that adding strength through resistance training may positively affect risk factors like insulin resistance, glucose metabolism, metabolic rate and blood pressure. You didn’t complete your profile so I cant tell if you do any exercise or what your activity levels are but looking at your diet, you are only consuming meat in one of your daily meals. Whilst you will source some protein from nuts, seeds and beans in your diet, if weight gain is your goal, I would suggest adding a bit more protein to at least one of your meals. Add a few servings of fatty fish such as salmon or sardines per week. Adding some cottage cheese or eggs as well to boost protein intake, unless you are specifically choosing to avoid these foods. All of these protein sources are slow digesting as they contain fat within them which slows their digestion rate.

Sodium and Potassium

I monitor everything I eat so carefully; I get 7-12 servings of vegetables and fruits in a day (usually about 2:1 veg:fruit ratio, although on the especially high produce days its more like 3:1) and I make everything at home, avoiding almost all pre-made foods. I never eat out. My diet is around 1600-1800 calories a day (5’11 female, 24, 160 lbs, 24% body fat) but my sodium intake is still usually around 2500 mg and my potassium is only around 3,600 mg. A couple times a week I will have turkey bacon, and I do eat eggs, skim milk and reduced fat cheese which is fairly high in salt. My diet is around 40-44% carb, 25-30% protein and 30-32% fat (I make sure sat fat stays under 10%). If I am doing everything right, why are nutrition forums saying my K:NaCl ratio should be 4:1 when mine is closer to 1:1 or 2:1 on a really good day? Is this bad?


I would not get too concerned about these ratio values, whilst your sodium intake is a little high, the American 2010 Dietary Guidelines outlined that dietary sodium should be limited to 2300 mg/d and potassium limited to 4700 mg/d. These are figures that less than 0.1% of the population meet, so you are doing pretty good. In addition to this there is still plenty of conflicting evidence as to the risks of consuming excess salt, only recently a study involving 6,250 subjects found no strong evidence that cutting salt intake reduces the risk for heart attacks, strokes or death. Its easy to look at the details too much and miss the big picture, maintaining a balanced diet with adequate fruit and veg and avoiding processed foods is the key. You are following your diet quite closely which is great, and you are only slightly over the recommended sodium allowance. You mentioned that you are consuming some products that are fairly high in salt, if you want you can reduce these. However I would say as your diet is very rich in fruit and vegetables and your meals are home cooked and non processed, I think you can afford to have a few treats from time to time!!

Vitamin and Mineral overdose

I am trying to create the ultimate salad. A salad that contains at least 100% DV in 13 vitamins and 18 minerals and keeping it under 600 calories. It’s not that easy. I have read that it can be dangerous if you consume too much vitamins and minerals. What is the likelihood of consuming too much through food? No supplements. If there are certain vitamins and minerals that are more dangerous than others, can you please distinguish them from each other? Thank you.


Unlike vitamin tablets, if you are following a varied and balanced diet it is not that easy to overdose on vitamins or minerals found in food. Unless you specifically ate the same food in huge amounts every single day, then you might have a problem. Additionally some vitamins that are dangerous in high doses are not found in fruits and vegetables. Retinol otherwise known as Vitamin A can cause problems at high doses. However in fruits and vegetables they contain a pre-cursor to Vitamin A called Beta-carotene. When consumed the body will convert Beta-Carotene as and when required to Vitamin A. If excess Beta-carotene is consumed the body can get rid of it, so its difficult to overdose on it. As long as you are eating a balanced diet and including fruit and vegetables, you should not be at risk of overdosing.

Folic acid daily intake

Concerned about recent data on too much folic acid and the fact that multivitamins contain the RDA of 400mgs already. I believe I can get almost all I need through a good diet so thinking about half a multiple daily to limit folic acid. Also, is the danger from too much only pertain to folic acid and not folate? In other words, if I consume 600 mg daily and only 200 are actually folic acid, is that a problem? Thanks so much!


It is always better to source vitamins and minerals from food. However I appreciate some people want to ensure they are getting all their nutrients and like to take something to supplement their diet. I would suggest in your case to look for a vitamin formula that supplies folate rather than folic acid, look for methyl folate, Metfolin, or “5-MTHF” on the label.

Low nickle diet

I am wondering if whey protein contains any traces of nickle in them? And should I be avoiding whey that has traces of soy?


It is difficult to comment regarding whey without knowing the specific product. Whey is processed in a variety of ways and in some cases other substances are added to the final product such as minerals, flavourings and sweeteners. If the product is pure without additives I would not expect whey to contain any significant amount of nickel as it is derived from milk which is permitted on low nickel diets. Soy should be avoided and some protein powder formulations contain soy protein. Some whey protein products may include Soy Lecithin which is a fat used as part of manufacturing process of the product. Soy Lecithin could potentially contain some trace of nickel as Soy is a rich source of Nickel so you may need to be careful. I have seen whey protein products that are free from most additives so you will need to do a little research to find a product that’s best for you.